技术领域technical field
本公开一般涉及用于接收射频（RF）信号的接收机电路，且更具体地涉及包括调谐网络的接收机和设备。 The present disclosure relates generally to receiver circuits for receiving radio frequency (RF) signals, and more particularly to receivers and devices including tuning networks. the
背景技术Background technique
射频（RF）通信设备包括配置成从天线接收RF信号且在一些情况下从天线传达RF信号的电路。RF通信设备用在各种应用中，包括蜂窝电话、无绳电话、个人数字助理（PDA）、计算机、无线电以及其它配置成发送和/或接收射频信号的电子设备。 A radio frequency (RF) communication device includes circuitry configured to receive, and in some cases communicate, RF signals from an antenna. RF communication devices are used in a variety of applications, including cellular telephones, cordless telephones, personal digital assistants (PDAs), computers, radios, and other electronic devices configured to transmit and/or receive radio frequency signals. the
为了发送和接收RF信号，RF通信设备包括可配置成将接收电路调谐至适当频带的调谐电路。在一些调幅（AM）数字调谐器中，当用户从AM频带内的一个频道改变至另一个频道时，RF通信设备暂时使音频信号空白，执行调谐功能以将调谐器电路校准至所选频道，然后在新频道上提供音频信号。通常，很多数字接收机在用户选择新频道和接收机音频输出之间引入短暂延迟。 In order to transmit and receive RF signals, RF communication devices include tuning circuitry configurable to tune the receiving circuitry to an appropriate frequency band. In some amplitude modulation (AM) digital tuners, when the user changes from one channel to another within the AM band, the RF communication device temporarily blanks the audio signal, performing a tuning function to calibrate the tuner circuitry to the selected channel, The audio signal is then provided on the new channel. Typically, many digital receivers introduce a short delay between the user selecting a new channel and the receiver's audio output. the
发明内容Contents of the invention
在一实施例中，包括调谐网络的接收机包括用于从天线接收射频信号的输入端子和可调谐电路，该可调谐电路包括耦合至输入端子的输入端、至少一个控制输入端和输出端子。可调谐电路包括变容二极管，该变容二极管具有耦合至输入端子的第一电极和耦合至电源端子的第二电极。接收机还包括控制电路，该控制电路耦合至输出端子和至少一个控制输入端。控制电路接收无线电频道选择并响应于无线电频道选择基于与可调谐电路相关联的预定电感确定变容二极管的电容。 In an embodiment, a receiver comprising a tuning network comprises an input terminal for receiving a radio frequency signal from an antenna and a tunable circuit comprising an input coupled to the input terminal, at least one control input and an output terminal. The tunable circuit includes a varactor diode having a first electrode coupled to an input terminal and a second electrode coupled to a power supply terminal. The receiver also includes a control circuit coupled to the output terminal and at least one control input. A control circuit receives a radio channel selection and determines a capacitance of the varactor based on a predetermined inductance associated with the tunable circuit in response to the radio channel selection. the
在实施例中，控制电路控制变容二极管以将可调谐电路调谐至两个不同频率，当可调谐电路在两个不同频率的每一个处振荡时确定可调谐电路的一个或 多个参数并且基于一个或多个参数确定预定电感。接收机还包括存储器，且其中控制电路被配置成针对射频范围的每个频率计算变容二极管的电容并将与每个频率下的电容对应的值存储在存储器中。两个不同频率对应于射频范围的不同频道。 In an embodiment, the control circuit controls the varactor diode to tune the tunable circuit to two different frequencies, determines one or more parameters of the tunable circuit when the tunable circuit oscillates at each of the two different frequencies and based on One or more parameters determine the predetermined inductance. The receiver also includes a memory, and wherein the control circuit is configured to calculate the capacitance of the varactor for each frequency of the radio frequency range and store a value corresponding to the capacitance at each frequency in the memory. The two different frequencies correspond to different channels of the radio frequency range. the
在实施例中，接收机还包括耦合至输出端子的低噪声放大器；频率检测电路，用于在校准期间监控来自可调谐电路的振荡，其中控制电路基于振荡确定预定电感；能量电路，该能量电路被配置成在校准期间将信号注入可调谐电路以使可调谐电路谐振。 In an embodiment, the receiver further comprises a low noise amplifier coupled to the output terminal; a frequency detection circuit for monitoring oscillations from the tunable circuit during calibration, wherein the control circuit determines a predetermined inductance based on the oscillations; an energy circuit for the energy circuit A signal is configured to inject a signal into the tunable circuit during calibration to cause the tunable circuit to resonate. the
在另一个实施例中，一种方法包括：在接收机上接收射频调节信号；响应于接收射频调节信号，基于可调谐电路的预定参数确定可调谐电路的变容二极管设置以供调谐至所选无线电频道。该方法还包括响应于确定变容二极管设置将变容二极管设置应用于可调谐电路的变容二极管以接收所选无线电频道。 In another embodiment, a method includes: receiving a radio frequency tuning signal at a receiver; in response to receiving the radio frequency tuning signal, determining a varactor setting of a tunable circuit based on predetermined parameters of the tunable circuit for tuning to a selected radio channel. The method also includes applying a varactor setting to a varactor of the tunable circuit to receive the selected radio channel in response to determining the varactor setting. the
在又一实施例中，一种包括调谐网络的设备包括用于接收射频信号的天线和接收机电路，该接收机电路包括耦合至天线的输入端子。该接收机电路包括变容二极管，该变容二极管包括耦合至输入端子的第一端子和接地的第二端子。该接收机电路还包括控制器，该控制器耦合至输入端子和变容二极管且包括控制输入端。控制器在控制输入端接收射频频道选择，响应于射频频道选择基于天线的预定电感确定变容二极管的电容，并且响应于确定电容来配置变容二极管以在对应于射频频道选择的频率下谐振。 In yet another embodiment, an apparatus including a tuning network includes an antenna for receiving radio frequency signals and a receiver circuit including an input terminal coupled to the antenna. The receiver circuit includes a varactor diode including a first terminal coupled to an input terminal and a second terminal coupled to ground. The receiver circuit also includes a controller coupled to the input terminal and the varactor and including a control input. A controller receives a radio frequency channel selection at a control input, determines a capacitance of the varactor based on a predetermined inductance of the antenna in response to the radio frequency channel selection, and configures the varactor to resonate at a frequency corresponding to the radio frequency channel selection in response to the determined capacitance. the
在实施例中，设备，还包括存储器，存储器耦合至控制器且适配成存储与变容二极管的电容值对应的多个值。控制器响应于确定电容存储多个值中的、与电容对应的值。控制器响应于接收射频频道选择通过在多个值中查找电容来确定电容。 In an embodiment, the apparatus further includes a memory coupled to the controller and adapted to store a plurality of values corresponding to capacitance values of the varactor diodes. The controller stores a value of the plurality of values corresponding to the capacitance in response to determining the capacitance. The controller determines the capacitance by looking up the capacitance among a plurality of values in response to receiving a radio frequency channel selection. the
在实施例中，控制器在加电期间或在频带之间切换时接收控制信号，且响应于控制信号，控制器：将包括变容二极管的可调谐电路调谐至两个不同频率；在两个不同频率的每个频率下监控可调谐电路的振荡以确定可调谐电路的一个或多个参数；以及基于一个或多个参数配置用于计算变容二极管的电容的方程式。控制器利用方程式确定变容二极管的电容。 In an embodiment, the controller receives a control signal during power-up or when switching between frequency bands, and in response to the control signal, the controller: tunes the tunable circuit comprising varactor diodes to two different frequencies; monitoring oscillation of the tunable circuit at each of the different frequencies to determine one or more parameters of the tunable circuit; and configuring an equation for calculating capacitance of the varactor based on the one or more parameters. The controller uses the equation to determine the capacitance of the varactor. the
在实施例中，控制器通过以下操作校准可调谐电路：配置变容二极管以在 两个不同频率下谐振；以及监控可调谐电路在两个不同频率下的输出以确定可调谐电路的基本固定的参数；以及其中控制器基于基本固定的参数和射频频道选择自动计算变容二极管的电容。控制器在制造过程的生产设计阶段和测试阶段之一校准可调谐电路。控制器响应于将接收机电路从不同操作模式切换至AM操作模式的控制信号校准可调谐电路。 In an embodiment, the controller calibrates the tunable circuit by: configuring a varactor to resonate at two different frequencies; and monitoring the output of the tunable circuit at two different frequencies to determine a substantially fixed value of the tunable circuit. parameters; and wherein the controller automatically calculates the capacitance of the varactor based on the substantially fixed parameters and radio frequency channel selection. The controller calibrates the tunable circuit during one of the production design phase and the test phase of the manufacturing process. A controller calibrates the tunable circuit in response to a control signal that switches the receiver circuit from a different mode of operation to an AM mode of operation. the
附图说明Description of drawings
图1是包括带可调谐电路的接收机电路的系统的实施例的框图。 Figure 1 is a block diagram of an embodiment of a system including receiver circuitry with tunable circuitry. the
图2是包括图1的可调谐电路和包括校准电路的调幅（AM）前端电路的组件的系统的一部分的部分电路图和部分框图。 2 is a partial circuit diagram and partial block diagram of a portion of a system including components of the tunable circuit of FIG. 1 and an amplitude modulation (AM) front-end circuit including a calibration circuit. the
图3是包括图1的可调谐电路的实施例且包括校准电路的实施例的系统的实施例的部分电路图和部分框图。 3 is a partial circuit diagram and partial block diagram of an embodiment of a system including an embodiment of the tunable circuit of FIG. 1 and including an embodiment of a calibration circuit. the
图4是包括天线、印刷电路板、图1的可调谐电路以及低噪声放大器的系统的一部分的示例的电路图。 4 is a circuit diagram of an example of a portion of a system including an antenna, a printed circuit board, the tunable circuit of FIG. 1, and a low noise amplifier. the
图5是配置方程式以确定接收机电路的变容二极管设置的方法的实施例的流程图。 5 is a flowchart of an embodiment of a method of configuring equations to determine varactor settings for a receiver circuit. the
图6是提供与所选调谐频率相对应的信号的方法的实施例的流程图。 6 is a flowchart of an embodiment of a method of providing a signal corresponding to a selected tuning frequency. the
在以下的描述中，在不同附图中使用相同的附图标记表示相似或相同的部件。 In the following description, the same reference numerals are used in different drawings to designate similar or identical components. the
具体实施方式Detailed ways
在没有用于显示调谐频率的显示器的传统模拟调谐无线电系统中，无线电系统的表观调谐速度直接与用户经验有关，因为人耳是检测站的成功调谐的唯一设备。尽管包括调幅（AM）无线电接收机的无线电可包括利用外部电感器（通常是AM铁氧体或空中环形天线形式）自动调谐的AM前端电容器，但无线电的微控制器需要时间来执行将AM前端电容器适当调谐至所选频带内的射频范围的射频频道所需的各种计算。尽管在每个频率调谐命令下自动调谐电容器是可能的，但这种调谐使用的时间比当用户使用模拟调谐刻度盘调谐无线电时用户通常允许的各调节之间的时间更长。具体地，传统的利用模拟刻度盘 的AM站调谐依靠通过人耳检测可能的站，但通过微处理器执行调谐计算导致延迟，这破坏了这种用户检测且阻碍传统模拟无线电调谐感受，尤其是当相对较快地转动调谐轮时。因此，用于AM无线电的调谐应比这种常规自动调谐所允许的要快。 In conventional analog tuned radio systems without a display to show the tuning frequency, the apparent tuning speed of the radio system is directly related to the user experience, since the human ear is the only instrument for successful tuning at the detection station. Although a radio including an amplitude modulation (AM) radio receiver may include an AM front-end capacitor that is automatically tuned using an external inductor (usually in the form of an AM ferrite or an air loop antenna), it takes time for the radio's microcontroller to implement the AM front-end Various calculations are required for the capacitor to be properly tuned to an RF channel in the RF range within the selected frequency band. While it is possible to automatically tune the capacitor at each frequency tuning command, such tuning takes longer than the time between adjustments that a user typically allows when the user tunes the radio using an analog tuning dial. Specifically, traditional AM station tuning with an analog dial relies on detecting possible stations by the human ear, but performing tuning calculations through a microprocessor causes delays that destroy this user detection and hinder the traditional analog radio tuning experience, especially When turning the tuning wheel relatively quickly. Therefore, tuning for AM radio should be faster than such conventional auto-tuning allows. the
以下描述接收机电路的实施例，其利用AM调谐器在加电或频带切换（诸如从一个频带切换至另一个，例如从任意其它频带切换至AM频带）时的自动调谐以将无线电自动调谐至两个已知频率，记录AM调谐器变容二极管设置，且随后对于每个后续调谐频率计算变容二极管的电容。在一种情况下，对于每个后续频率调谐，微处理器根据方程式计算变容二极管电容并将所计算的值写入电容器组。 An embodiment of a receiver circuit is described below that utilizes automatic tuning of an AM tuner upon power-up or band switching (such as switching from one band to another, for example switching from any other band to an AM band) to automatically tune the radio to For two known frequencies, the AM tuner varactor setting is recorded, and then the capacitance of the varactor is calculated for each subsequent tuned frequency. In one case, for each subsequent frequency tuning, the microprocessor calculates the varactor capacitance according to the equation and writes the calculated value to the capacitor bank. the
图1是包括带可调谐电路106的接收机电路102的系统100的实施例的框图。接收机电路102包括配置成从信号源104接收射频信号的输入端子。接收机电路102包括可调谐电路106，该可调谐电路106包括连接至输入端子的第一端子和接地的第二端子。接收机电路102还包括连接至输入端子的前端电路108和激发电路112。接收机电路102还包括微控制单元（MCU）110，该微控制单元（MCU）110连接至前端电路108、激发电路112和可调谐电路106的变容二极管116。变容二极管116包括连接至输入端子的第一端子和接地的第二端子。可调谐电路106还包括电感器114，该电感器114包括连接至输入端子的第一端子和接地的第二端子。 FIG. 1 is a block diagram of an embodiment of a system 100 including a receiver circuit 102 with a tunable circuit 106 . The receiver circuit 102 includes an input terminal configured to receive a radio frequency signal from a signal source 104 . The receiver circuit 102 includes a tunable circuit 106 including a first terminal connected to an input terminal and a second terminal connected to ground. The receiver circuit 102 also includes a front-end circuit 108 and a excitation circuit 112 connected to the input terminals. Receiver circuit 102 also includes a micro control unit (MCU) 110 connected to front end circuit 108 , excitation circuit 112 , and varactor diode 116 of tunable circuit 106 . The varactor 116 includes a first terminal connected to the input terminal and a second terminal connected to ground. The tunable circuit 106 also includes an inductor 114 including a first terminal connected to the input terminal and a second terminal connected to ground. the
在操作期间，MCU110控制变容二极管116和激发电路112以将可调谐电路116配置成在两个已知频率谐振，并记录变容二极管设置。根据所记录的变容二极管设置，能够容易地确定可调谐电路106和任意相关联外部电路的固定值。假设可调谐电路106的电感器/电容器网络具有固定电感，则可根据以下方程式确定可调谐电路106的总电容（包括变容二极管116和任意固定电容）： During operation, MCU 110 controls varactor 116 and excitation circuit 112 to configure tunable circuit 116 to resonate at two known frequencies, and records the varactor settings. Fixed values for tunable circuitry 106 and any associated external circuitry can be readily determined from the recorded varactor settings. Assuming that the inductor/capacitor network of tunable circuit 106 has a fixed inductance, the total capacitance of tunable circuit 106 (including varactor 116 and any fixed capacitance) can be determined according to the following equation:
在方程式1中，谐振频率（fres）与可调谐电路106的电感（L）和电容（C）的平方根成反比，该电容（C）包括例如来自变容二极管116、电感器114和外部PCB迹线等的固定寄生、前端电路108的输入电容以及变容二极管116的变化电容。 In Equation 1, the resonant frequency (fres ) is inversely proportional to the square root of the inductance (L) and capacitance (C) of the tunable circuit 106 including, for example, Fixed parasitics of traces etc., input capacitance of front-end circuit 108 , and varying capacitance of varactor diode 116 .
假设电感和固定电容是静态的，则能够以合理精确度计算可变电容，以调谐至期望频率而不需要后续校准（至少关于所选频带）。因此，响应于通电操作或频带切换操作，MCU110控制可调谐电路106并确定可调谐电路106的固定组件的值，对于用于配置变容二极管116的适当电容的后续计算可将该固定组件的值视为静态值。 Assuming the inductance and fixed capacitance are static, the variable capacitance can be calculated with reasonable accuracy to tune to the desired frequency without subsequent calibration (at least with respect to the selected frequency band). Thus, in response to a power-on operation or a band-switching operation, MCU 110 controls tunable circuit 106 and determines values of fixed components of tunable circuit 106 that can be determined by subsequent calculations for the appropriate capacitance for configuring varactor 116 Treated as a static value. the
变容二极管116的计算的精确度适于在操作期间使用。由变容二极管116和电感器114形成的谐振网络一般提供约40的质量因数（Q），所以即使变容二极管116的电容偏离百分之几导致调谐频率偏离，接收机电路102的性能也不会显著劣化。通过基于固定电感值和任意固定电容器值根据以上的方程式1插值或计算变容二极管116的设置，能动态调谐接收机电路102而无需进一步校准，使得可能对诸如用户调谐射频刻度盘之类的调谐调节提供基本上即时的响应。 The accuracy of the calculation of the varactor 116 is suitable for use during operation. The resonant network formed by varactor 116 and inductor 114 typically provides a quality factor (Q) of about 40, so even if the capacitance of varactor 116 deviates by a few percent resulting in a shift in tuning frequency, the performance of receiver circuit 102 will not vary. will deteriorate significantly. By interpolating or calculating the varactor 116 setting according to Equation 1 above based on a fixed inductance value and an arbitrary fixed capacitor value, the receiver circuit 102 can be dynamically tuned without further calibration, making it possible for tuning such as user-tuned radio frequency dials Tuning provides an essentially instant response. the
图2是包括图1的可调谐电路106和包括校准电路218的调幅（AM）前端电路201的组件的系统200的一部分的部分电路图和部分框图。系统200包括连接至AM前端电路201的数字信号处理器202。可调谐电路106包括电感器114，该电感器114包括接地的第一端子和连接至电容器204的第一电极的第二端子，该电容器204具有连接至AM前端电路201的输入端子的第二电极。可调谐电路106还包括变容二极管116，该变容二极管116包括连接至输入端子的第一端子和接地的第二端子。 2 is a partial circuit diagram and partial block diagram of a portion of a system 200 including components of the tunable circuit 106 of FIG. 1 and an amplitude modulation (AM) front-end circuit 201 including a calibration circuit 218 . The system 200 includes a digital signal processor 202 connected to an AM front-end circuit 201 . The tunable circuit 106 includes an inductor 114 including a first terminal connected to ground and a second terminal connected to a first electrode of a capacitor 204 having a second electrode connected to an input terminal of the AM front-end circuit 201 . The tunable circuit 106 also includes a varactor diode 116 including a first terminal connected to the input terminal and a second terminal connected to ground. the
AM前端电路201包括低噪声放大器（LNA）206，该低噪声放大器（LNA）206包括连接至输入端子的输入端和连接至混频器208的输出端。混频器208包括第一输出以向同相可编程增益放大器（I-PGA）210提供同相输出信号。混频器208还包括第二输出以向正交PGA（Q-PGA）212提供正交输出信号。I-PGA210包括连接至同相模数转换器（I-ADC）214的输出，该同相模数转换器（I-ADC）214具有连接至DSP202的输出。Q-PGA212包括连接至正交ADC（Q-ADC）216的输出，该正交ADC（Q-ADC）216具有连接至DSP202的输出。AM前端电路201还包括连接至MCU110的校准电路218和连接至输入端子的端子。MCU110连接至变容二极管116。MCU110配置成利用以上的方程式1计算变容二极管116的设置并将变容二极管116配置成提供基本上对 应于调谐调节输入的谐振频率。 The AM front-end circuit 201 includes a low noise amplifier (LNA) 206 including an input connected to an input terminal and an output connected to a mixer 208 . Mixer 208 includes a first output to provide an in-phase output signal to in-phase programmable gain amplifier (I-PGA) 210 . The mixer 208 also includes a second output to provide a quadrature output signal to a quadrature PGA (Q-PGA) 212 . I-PGA 210 includes an output connected to an in-phase analog-to-digital converter (I-ADC) 214 , which has an output connected to DSP 202 . Q-PGA 212 includes an output connected to quadrature ADC (Q-ADC) 216 , which has an output connected to DSP 202 . The AM front-end circuit 201 also includes a calibration circuit 218 connected to the MCU 110 and a terminal connected to an input terminal. The MCU 110 is connected to a varactor 116 . The MCU 110 is configured to calculate the setting of the varactor 116 using Equation 1 above and configure the varactor 116 to provide a resonant frequency substantially corresponding to the tuning adjustment input. the
在示例中，响应于加电操作或频带切换操作，MCU110控制变容二极管116以将可调谐电路106调谐至所选频带内的两个已知频率。在一些情况下，MCU110控制校准电路218以将激发电压（或音调）注入可调谐电路106，导致可调谐电路106在谐振频率振荡。MCU110然后基于振荡测量可调谐电路106的一个或多个参数。基于在两个频率下变容二极管116的已知值，该一个或多个参数可用于确定可调谐电路106的固定电容值和电感器值，可将它们用于配置以上的方程式1。随后，响应于频率调节，MCU110使用以上的方程式1和所确定的参数来计算变容二极管116的值并利用所计算的值配置变容二极管116。 In an example, in response to a power up operation or a band switching operation, MCU 110 controls varactor 116 to tune tunable circuit 106 to two known frequencies within the selected frequency band. In some cases, MCU 110 controls calibration circuit 218 to inject an excitation voltage (or tone) into tunable circuit 106 , causing tunable circuit 106 to oscillate at a resonant frequency. MCU 110 then measures one or more parameters of tunable circuit 106 based on the oscillations. Based on the known values of varactor 116 at two frequencies, these one or more parameters can be used to determine fixed capacitance and inductor values for tunable circuit 106, which can be used to configure Equation 1 above. Then, in response to the frequency adjustment, MCU 110 uses Equation 1 above and the determined parameters to calculate the value of varactor 116 and configures varactor 116 using the calculated value. the
图3是包括图1的可调谐电路106的实施例且包括校准电路218的实施例的系统300的实施例的部分电路图和部分框图。在所示示例中，电感器114由电感器302（AM天线）和相关联的电压源304表示，该电压源304表示由天线接收的电压信号。电压源304包括接地的第一端子和连接至电感器302的第一端子的第二端子。电感器302具有连接至AC耦合电容器204的第一电极的第二端子，该AC耦合电容器204具有连接至LNA206的输入端的第二电极。可调谐电路106还包括变容二极管116，该变容二极管116包括接地的第一端子和连接至LNA206的输入端的第二端子。LNA206的输入端的输入电压是变容二极管116两端的输出电压（VO）。 3 is a partial circuit diagram and partial block diagram of an embodiment of a system 300 including an embodiment of the tunable circuit 106 of FIG. 1 and including an embodiment of the calibration circuit 218 . In the example shown, inductor 114 is represented by inductor 302 (AM antenna) and associated voltage source 304 representing the voltage signal received by the antenna. The voltage source 304 includes a first terminal connected to ground and a second terminal connected to the first terminal of the inductor 302 . Inductor 302 has a second terminal connected to a first electrode of AC coupling capacitor 204 having a second electrode connected to an input terminal of LNA 206 . Tunable circuit 106 also includes a varactor diode 116 including a first terminal connected to ground and a second terminal connected to an input terminal of LNA 206 . The input voltage at the input of LNA 206 is the output voltage (VO ) across varactor diode 116 .
系统300还包括校准电路218，该校准电路218包括连接至电压源304的第一端子和连接至LNA206的输入端的第二端子。系统300还包括MCU110，其连接至校准电路218和变容二极管116。MCU110还连接至存储器310，该存储器310包括一个或多个变容二极管设置312。 System 300 also includes a calibration circuit 218 that includes a first terminal connected to voltage source 304 and a second terminal connected to the input of LNA 206 . System 300 also includes MCU 110 connected to calibration circuit 218 and varactor 116 . The MCU 110 is also connected to a memory 310 that includes one or more varactor settings 312 . the
校准电路218包括配置成检测LNA206输入端处的振荡的谐振频率的频率检测电路306。校准电路218还包括能量电路308，该能量电路308响应于MCU110来将电压或脉冲施加到AM前端（调谐网络）201。 The calibration circuit 218 includes a frequency detection circuit 306 configured to detect the resonant frequency of the oscillation at the input of the LNA 206 . The calibration circuit 218 also includes an energy circuit 308 that is responsive to the MCU 110 to apply a voltage or pulse to the AM front end (tuning network) 201 . the
如先前所讨论的，MCU110控制校准电路218和变容二极管116来将可调谐电路106调谐至两个不同的频率，监控谐振频率响应，并确定适合配置方程式1的参数。因此，MCU110可利用这些参数配置方程式1，使得可能随后 计算变容二极管116的设置以调谐至所选频率而无需再校准可调谐电路106。 As previously discussed, MCU 110 controls calibration circuit 218 and varactor 116 to tune tunable circuit 106 to two different frequencies, monitor the resonant frequency response, and determine parameters suitable for configuring Equation 1 . Thus, the MCU 110 can configure Equation 1 with these parameters, making it possible to subsequently calculate the setting of the varactor 116 to tune to the selected frequency without recalibrating the tunable circuit 106. the
在特定示例中，校准电路218使用能量电路308向可调谐电路106提供电能以实现谐振。校准电路218使用频率检测电路306来检测谐振频率，且MCU110使用频率检测信息来确定变容二极管116的值，这些值可被存储在存储器310中作为变容二极管设置312。每次MCU110利用方程式1确定新的变容二极管设置，MCU110可在存储器310中存储变容二极管116的设置。 In a particular example, calibration circuit 218 provides power to tunable circuit 106 using energy circuit 308 to achieve resonance. Calibration circuit 218 uses frequency detection circuit 306 to detect the resonant frequency, and MCU 110 uses the frequency detection information to determine varactor 116 values, which may be stored in memory 310 as varactor settings 312 . Each time MCU 110 determines a new varactor setting using Equation 1 , MCU 110 may store the setting for varactor 116 in memory 310 . the
尽管以上示例描述了在加电和在频带之间切换时的调谐，但也可在制造期间确定变容二极管116的设置。例如，在生产测试过程中，主控制器可控制MCU110调节变容二极管116的值以与固定外部电感器（诸如电感器304）谐振至两个不同的频率。校准电路318可在正常操作中对于不同的调谐频率产生可用于计算变容二极管116的设置的数据。为了在该生产测试期间精确确定变容二极管116的设置，期望知晓天线电感值或外部电感值以及在正常操作中可能存在的寄生电容。 While the above examples describe tuning at power-up and switching between frequency bands, the varactor 116 setting may also be determined during manufacture. For example, during production testing, the main controller may control the MCU 110 to adjust the value of the varactor 116 to resonate with a fixed external inductor (such as inductor 304 ) to two different frequencies. The calibration circuit 318 can generate data that can be used to calculate the setting of the varactor 116 for different tuning frequencies in normal operation. In order to accurately determine the varactor 116 setting during this production test, it is desirable to know the antenna or external inductance value and the parasitic capacitance that may exist in normal operation. the
在可选实施例中，变容二极管116可实现为变容二极管组，可在生产测试期间通过施加已知电感并通过激发所得电路谐振来校准该变容二极管组。一旦已经校准该变容二极管组，则可在产品设计阶段基于用户提供的电感值确定变容二极管设置。 In an alternative embodiment, varactor 116 may be implemented as a bank of varactors that may be calibrated during production testing by applying a known inductance and by exciting the resulting circuit resonance. Once the varactor bank has been calibrated, the varactor settings can be determined during the product design phase based on the user-supplied inductance value. the
在又一实施例中，在产品设计阶段，一旦基本确定天线设计，则设计者将知晓或具有预测电感的足够信息。在这种情况下，可将可调谐电路106手动调谐至两个或更多频率，且可记录变容二极管读数然后基于该信息将这些读数用于计算变容二极管116的设置。 In yet another embodiment, at the product design stage, once the antenna design is substantially determined, the designer will know or have sufficient information to predict the inductance. In this case, the tunable circuit 106 can be manually tuned to two or more frequencies, and the varactor readings can be recorded and then used to calculate the setting of the varactor 116 based on this information. the
在又一示例中，MCU110可利用在频带之间切换时和/或在加电期间通过调谐至两个已知频率积累的数据来计算对于频带上频率的变容二极管设置312，使得MCU110随后能通过在存储器310中查找变容二极管设置312并将它们应用于变容二极管116来更新变容二极管116的设置以提供期望的谐振频率。 In yet another example, MCU 110 may use data accumulated by tuning to two known frequencies when switching between frequency bands and/or during power-up to calculate varactor settings 312 for frequencies across the bands such that MCU 110 can then The settings of varactor 116 are updated to provide the desired resonant frequency by looking up varactor settings 312 in memory 310 and applying them to varactor 116 . the
尽管上述描述假设固定电感和可变电容，但应意识到可将天线、电路板和前端电路建模为多个分立电路元件。以下参考图4描述天线、印刷电路板（PCB）和AM前端电路406的电路模型的示例。 Although the above description assumes fixed inductance and variable capacitance, it should be appreciated that the antenna, circuit board, and front-end circuitry can be modeled as multiple discrete circuit elements. An example of a circuit model of the antenna, printed circuit board (PCB), and AM front-end circuitry 406 is described below with reference to FIG. 4 . the
图4是包括天线402、印刷电路板（PCB）404和诸如图1-3的可调谐电路106的一部分和图2中的LNA206之类的AM前端电路406的系统400的一部分的示例的电路图。将天线402建模为表示所接收的RF信号的电压源410，其包括接地的第一端子和连接至电阻器412的第一端子的第二端子，电阻器412表示由天线402造成的损耗并具有连接至电感器414的第一端子的第二端子。电感器414具有连接至节点408并通过天线402连接至寄生电容器416的第一电极的第二端子，该寄生电容器416具有接地的第二电极。将PCB404建模为与电容器416并联连接的电容器418。PCB寄生电容器418包括连接至节点408的第一电极和接地的第二端子。 4 is a circuit diagram of an example of a portion of a system 400 including an antenna 402 , a printed circuit board (PCB) 404 , and an AM front-end circuit 406 such as a portion of the tunable circuit 106 of FIGS. 1-3 and the LNA 206 in FIG. 2 . The antenna 402 is modeled as a voltage source 410 representing the received RF signal, which includes a first terminal connected to ground and a second terminal connected to the first terminal of a resistor 412, which represents the losses caused by the antenna 402 and There is a second terminal connected to the first terminal of the inductor 414 . Inductor 414 has a second terminal connected to node 408 and through antenna 402 to a first electrode of parasitic capacitor 416 having a second electrode connected to ground. PCB 404 is modeled as capacitor 418 connected in parallel with capacitor 416 . PCB parasitic capacitor 418 includes a first electrode connected to node 408 and a second terminal connected to ground. the
AM前端电路406包括可变电阻器420，该可变电阻器420具有连接至节点408的第一端子和接地的第二端子。AM前端电路406还包括变容二极管116和LNA206。将变容二极管116建模为可变电容器422，该可变电容器422包括连接至节点408的第一电极和连接至可变电阻器424的第一端子的第二电极，该可变电阻器424表示由可变电容器422造成的损耗并具有接地的第二端子。在这种情况下，变容二极管116被实现为电容器组，并且当电容器接入或断开时，杂散电阻值也改变。LNA206包括电阻器426，该电阻器426具有连接至节点408的第一端子和接地的第二端子。LNA206还包括电容器428，该电容器428包括连接至节点408的第一电极和接地的第二电极。 AM front-end circuit 406 includes a variable resistor 420 having a first terminal connected to node 408 and a second terminal connected to ground. AM front-end circuit 406 also includes varactor 116 and LNA 206 . Varactor diode 116 is modeled as a variable capacitor 422 comprising a first electrode connected to node 408 and a second electrode connected to a first terminal of a variable resistor 424, which represents losses due to variable capacitor 422 and has a second terminal connected to ground. In this case, the varactor diode 116 is implemented as a capacitor bank, and when the capacitor is switched in or out, the stray resistance value also changes. LNA 206 includes resistor 426 having a first terminal connected to node 408 and a second terminal connected to ground. LNA 206 also includes capacitor 428 including a first electrode connected to node 408 and a second electrode connected to ground. the
在所示示例中，AM前端电路406是电感器/电容器调谐电路，该电感器/电容器调谐电路将电压增益应用于从任意调谐AM站接收的RF信号。调谐电路包括来自天线的电感器414和来自变容二极管116的可变电容。可变电容器422使前端谐振，使得谐振频率与设备调谐至的AM站的频率相同。为了调谐至特定站，调节可变电容器422的电容使得AM前端406实现谐振。变容二极管116包括由可变电阻器424表示的杂散电阻值，其影响调谐电容器的Q因数。可变电阻器420提供对AM前端电路406的增益调节。电阻器426和电容器428是来自LNA206的阻抗和电容。 In the example shown, the AM front-end circuit 406 is an inductor/capacitor tuning circuit that applies a voltage gain to an RF signal received from any tuned AM station. The tuning circuit includes an inductor 414 from the antenna and a variable capacitance from the varactor 116 . A variable capacitor 422 resonates the front end so that the resonant frequency is the same as the frequency of the AM station to which the device is tuned. To tune to a particular station, the capacitance of variable capacitor 422 is adjusted such that AM front end 406 achieves resonance. Varactor 116 includes a stray resistance value represented by variable resistor 424 that affects the Q factor of the tuning capacitor. Variable resistor 420 provides gain adjustment for AM front-end circuit 406 . Resistor 426 and capacitor 428 are the impedance and capacitance from LNA 206 . the
即使利用这种更复杂的电路模型，当系统400处于谐振时，Q因数与总并联电阻成比例，但谐振频率仍与以上参考方程式1所描述的相当。至于图1中的可调谐电路106，即使具有可变电阻系统400仍提供约40的质量因数（Q）， 所以即使变容二极管116的电容值偏离百分之几导致调谐频率偏离，系统400的性能也不会显著劣化。 Even with this more complex circuit model, when the system 400 is at resonance, the Q factor is proportional to the total parallel resistance, but the resonant frequency is still comparable to that described above with reference to Equation 1. As for the tunable circuit 106 in FIG. 1, even with the variable resistance system 400 still provides a quality factor (Q) of about 40, so even if the capacitance value of the varactor 116 deviates by a few percent resulting in a deviation in the tuning frequency, the system 400 Performance will not be significantly degraded either. the
图5是配置方程式以确定接收机电路的变容二极管设置的方法500的实施例的流程图。在502，MCU110用与第一预定频率相对应的第一变容二极管设置来配置可调谐电感器/电容器（LC）网络的变容二极管。前进至504，MCU110控制校准电路218将第一音调注入可调谐LC网络。移动至506，MCU110使用校准电路218监控可调谐LC网络的输出处的振荡并将其与第一预定频率进行比较以确定与可调谐LC网络相关联的第一电感和第一电容。 5 is a flowchart of an embodiment of a method 500 of configuring equations to determine varactor settings for a receiver circuit. At 502 , MCU 110 configures varactors of a tunable inductor/capacitor (LC) network with a first varactor setting corresponding to a first predetermined frequency. Proceeding to 504, the MCU 110 controls the calibration circuit 218 to inject the first tone into the tunable LC network. Moving to 506 , the MCU 110 monitors the oscillation at the output of the tunable LC network using the calibration circuit 218 and compares it to the first predetermined frequency to determine a first inductance and a first capacitance associated with the tunable LC network. the
移动至508，MCU用与第二预定频率相对应的第二变容二极管设置配置变容二极管。前进至510，MCU110控制校准电路218将第二音调注入可调谐LC网络。行进至512，MCU110使用校准电路218监控可调谐LC网络的输出处的振荡并将其与第二预定频率进行比较以确定第二电感和第二电容。移动至514，MCU110基于第一和第二电容及第一和第二电感计算基本固定的电容和基本固定的电感。前进至516，MCU110利用基本固定的电容和基本固定的电感配置用于确定变容二极管设置的方程式，其中该方程式被配置成基于期望频率计算变容二极管设置。 Moving to 508, the MCU configures the varactor with a second varactor setting corresponding to a second predetermined frequency. Proceeding to 510, the MCU 110 controls the calibration circuit 218 to inject the second tone into the tunable LC network. Proceeding to 512 , the MCU 110 monitors the oscillation at the output of the tunable LC network using the calibration circuit 218 and compares it to a second predetermined frequency to determine a second inductance and a second capacitance. Moving to 514 , the MCU 110 calculates a substantially fixed capacitance and a substantially fixed inductance based on the first and second capacitances and the first and second inductances. Proceeding to 516 , MCU 110 configures an equation for determining the varactor setting using the substantially fixed capacitance and the substantially fixed inductance, wherein the equation is configured to calculate the varactor setting based on the desired frequency. the
在特定示例中，MCU110根据在两个不同的已知频率下获取的测量值来确定电感。随后，一旦已经配置方程式1，则MCU110利用方程式1动态计算变容二极管设置且无需可调谐电路106的再校准。在一些情况下，MCU110可存储变容二极管设置以供后续的再使用，使得可从存储器310检索变容二极管设置而无需进一步的计算。在特定的情况下，可在制造期间或之后（在校准期间）由MCU110填充变容二极管设置的查找表。 In a particular example, MCU 110 determines inductance from measurements taken at two different known frequencies. Then, once Equation 1 has been configured, the MCU 110 uses Equation 1 to dynamically calculate the varactor settings without recalibration of the tunable circuit 106 . In some cases, MCU 110 may store the varactor settings for subsequent reuse such that the varactor settings may be retrieved from memory 310 without further calculations. In certain cases, the look-up table of varactor settings may be populated by the MCU 110 during manufacturing or afterwards (during calibration). the
如上所讨论的，并非关于每个频率变化校准可调谐电路106，而是在加电时和在频带之间切换时利用两个已知频率配置变容二极管116。一旦根据两个已知频率下的谐振确定了方程式1的参数，随后可响应于频率调节动态计算变容二极管116的设置。以下参考图6描述确定变容二极管设置的方法的示例。 As discussed above, rather than calibrating the tunable circuit 106 for each frequency change, the varactor 116 is configured with two known frequencies when powered up and when switching between frequency bands. Once the parameters of Equation 1 are determined from the resonance at two known frequencies, the varactor 116 settings can then be dynamically calculated in response to frequency adjustments. An example of a method of determining a varactor setting is described below with reference to FIG. 6 . the
图6是提供与所选调谐频率相对应的信号的方法600的实施例的流程图。在602，MCU110接收频率调节信号。前进至604，接收机电路的MCU110响应于接收频率调节信号来动态计算变容二极管116的变容二极管设置以供调 谐至所选调谐频率。移动至606，MCU110将变容二极管设置应用于可调谐电路106的变容二极管110，以提供与所选调谐频率对应的谐振频率。 FIG. 6 is a flowchart of an embodiment of a method 600 of providing a signal corresponding to a selected tuning frequency. At 602, the MCU 110 receives a frequency adjustment signal. Proceeding to 604, the MCU 110 of the receiver circuit dynamically calculates the varactor setting of the varactor 116 for tuning to the selected tuning frequency in response to receiving the frequency adjustment signal. Moving to 606 , the MCU 110 applies a varactor setting to the varactor 110 of the tunable circuit 106 to provide a resonant frequency corresponding to the selected tuning frequency. the
前进至608，接收机电路在可调谐电路106的RF输入端接收射频（RF）信号。行进至610，可调谐电路106根据RF信号将对应于所选调谐频率的输出信号提供给可调谐电路106的输出端子。 Proceeding to 608 , the receiver circuit receives a radio frequency (RF) signal at the RF input of the tunable circuit 106 . Proceeding to 610, the tunable circuit 106 provides an output signal corresponding to the selected tuning frequency to an output terminal of the tunable circuit 106 based on the RF signal. the
在实施例中，在接收所述射频调节信号之前，该方法包括：在接收机的控制电路上接收用于在射频频带之间切换的控制信号；响应于控制信号将可调谐电路调谐至两个不同频率以确定所述可调谐电路的一个或多个参数；以及基于一个或多个参数配置用于动态计算变容二极管设置的方程式的设置。 In an embodiment, prior to receiving said radio frequency adjustment signal, the method comprises: receiving at a control circuit of a receiver a control signal for switching between radio frequency bands; responsive to the control signal, tuning the tunable circuit to two different frequencies to determine one or more parameters of the tunable circuit; and configuring settings of an equation for dynamically calculating varactor settings based on the one or more parameters. the
在实施例中，确定变容二极管设置包括：响应于接收所述射频调节信号利用包括数据预定参数的方程式计算所述变容二极管设置。在实施例中，可将变容二极管设置存储在接收机的存储器中。在可选实施例中，确定变容二极管设置包括在接收机的存储器中存储的表格中查找变容二极管设置。在该实施例中，在接收射频调节信号之前，该方法可包括：在制造期间确定变容二极管设置；以及在表格中所述变容二极管设置。 In an embodiment, determining a varactor setting includes calculating said varactor setting using an equation including data predetermined parameters in response to receiving said radio frequency adjustment signal. In an embodiment, the varactor settings may be stored in a memory of the receiver. In an alternative embodiment, determining the varactor settings includes looking up the varactor settings in a table stored in a memory of the receiver. In this embodiment, prior to receiving the radio frequency adjustment signal, the method may include: determining varactor settings during manufacturing; and said varactor settings in a table. the
尽管上述示例参照了调幅（AM）射频信号，但应该意识到还可将双频调谐技术应用于其它射频信号的接收，诸如调频（FM）无线电信号。尽管在利用数字接收机调谐至特定FM无线电站时的延迟可被很多收听者所接受，但如上所述当在无线电站之间切换时可基本消除校准延迟同时仍提供可接受的接收。 Although the above examples refer to amplitude modulated (AM) radio frequency signals, it should be appreciated that the dual frequency tuning technique can also be applied to the reception of other radio frequency signals, such as frequency modulated (FM) radio signals. While delays in tuning to a particular FM radio station with a digital receiver may be acceptable to many listeners, calibration delays may be substantially eliminated while still providing acceptable reception when switching between radio stations as described above. the
与以上参考图1-6描述的系统、电路和方法结合，接收机电路包括可调谐电路，该可调谐电路具有可由MCU配置的可变电容以提供期望的谐振频率。MCU110将可调谐电路106调谐至两个不同频率并监控谐振响应以确定方程式的参数，根据该方程式可容易地计算变容二极管116的电容。一旦确定参数，MCU110可利用方程式动态计算变容二极管116的设置且无需后续校准。因此，接收机电路可响应于用户的快速调谐调节而快速产生输出信号，且对于再校准不会再有延迟。 In conjunction with the systems, circuits and methods described above with reference to FIGS. 1-6, the receiver circuit includes a tunable circuit having a variable capacitance configurable by the MCU to provide a desired resonant frequency. The MCU 110 tunes the tunable circuit 106 to two different frequencies and monitors the resonant response to determine the parameters of the equation from which the capacitance of the varactor 116 can be easily calculated. Once the parameters are determined, the MCU 110 can use the equations to dynamically calculate the varactor 116 settings without subsequent calibration. Thus, the receiver circuit can quickly generate an output signal in response to a user's quick tuning adjustment, and there is no further delay for recalibration. the
虽然已参考优选实施例对本发明进行描述，但是本领域的技术人员将认识到可作形式和细节上的改变而不背离本发明的精神和范围。 Although the present invention has been described with reference to preferred embodiments, workers skilled in the art will recognize that changes may be made in form and detail without departing from the spirit and scope of the invention. the
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| PCT/CN2011/070844WO2012103679A1 (en) | 2011-01-31 | 2011-01-31 | Receiver circuit including tuning network |
| Publication Number | Publication Date |
|---|---|
| CN203747766Utrue CN203747766U (en) | 2014-07-30 |
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CN201190000923.7UExpired - Fee RelatedCN203747766U (en) | 2011-01-31 | 2011-01-31 | Receivers and equipment including tuning networks |
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| JP (1) | JP5778782B2 (en) |
| KR (1) | KR101732619B1 (en) |
| CN (1) | CN203747766U (en) |
| WO (1) | WO2012103679A1 (en) |
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| Date | Code | Title | Description |
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| CF01 | Termination of patent right due to non-payment of annual fee | Granted publication date:20140730 Termination date:20170131 |