A power detection module, a bandwidth-variable multi-mode power detection circuit and a receiver system

Abstract

The application discloses a power detection module, a bandwidth-variable multi-mode power detection circuit and a receiver system, wherein the power detection module comprises a detector for power detection and a detector peripheral circuit electrically connected with the detector; the detector peripheral circuit comprises a plurality of integral capacitors with different capacitances; the plurality of integral capacitors are connected in parallel; a first gating switch is connected in series on a branch where each integral capacitor is located; and the integral capacitors with different capacitances are gated by controlling the on-off of the first gating switch according to different detection modes, so that different detection modes are adapted. The application can adapt to various modulation modes, realize multi-mode and high-precision power detection, and comprehensively consider and balance power detection time and output noise suppression.

Description

Technical Field

[0001] This invention relates to the field of wireless communication technology, and more specifically, to a power detection module, a multi-mode power detection circuit with variable bandwidth, and a receiver system. Background Technology

[0002] In wireless communication, receiver systems are typically affected by factors such as transmit power, transmission distance, spatial fading, and multipath effects, resulting in a wide range of received signal levels that exceeds the receiver's processing capacity. For the receiver system, excessively high signal levels can cause hardware path saturation or blockage; conversely, excessively low signal levels lead to a low carrier-to-noise ratio, preventing the ADC from acquiring useful signals. Therefore, the receiver system must process the received signal to control its power within a certain range, ensuring that the amplitude exceeds the receiver sensitivity while preventing nonlinear distortion. To minimize the amplitude range of the receiver's output signal and ensure proper demodulation by the baseband module, the receiver system employs an automatic gain control (AGC) circuit to appropriately adjust the received signal power.

[0003] In AGC design, the power detection circuit plays a crucial role, serving as the basis for gain control decisions and enabling the circuit's gain regulation. With the development of modern communication technology, the performance of the power detection circuit has become increasingly important for wireless communication receiving systems. It needs to be able to detect various modulation signals with different bandwidths, and its detection accuracy, speed, and output noise reduction capabilities require further improvement. Initially, power detection circuits typically used a single detector for signal amplitude detection; however, a single detector cannot avoid interference from input noise. Therefore, researchers have proposed a power detection method and device for wireless communication systems, as well as a fast full-channel power detection circuit structure for adaptive channel selection. This method first uses a mixer to convert the received signal to a fixed intermediate frequency before detection, thus avoiding the influence of interference signals and improving the accuracy of power detection.

[0004] The existing power detection circuit design has the following defects:

[0005] 1. Inability to adapt to power detection of multiple modulation methods

[0006] While existing power detection technologies have introduced the concept of variable bandwidth, they are designed for fast frequency sweeps across a wide frequency band and do not provide specific circuit implementation methods. Furthermore, they do not consider the detection of waveforms with various modulation methods.

[0007] 2. Power detection time and output noise amplitude are uncontrollable.

[0008] Since the power detection time and output noise amplitude are directly related to the integrating capacitor of the detector, the design of the integrating capacitor is crucial. In existing technologies, the peripheral circuit of the detector uses only a single integrating capacitor with a fixed capacitance value, which cannot be selected based on the detection time and noise amplitude. Consequently, both the power detection time and the output noise amplitude are uncontrollable.

[0009] 3. The detector has a long voltage drop time.

[0010] When a detector uses a large integrating capacitor to reduce noise amplitude, the voltage drop time of the capacitor slows down, resulting in an excessively long detection interval. Current technology does not consider this application scenario and cannot adjust the voltage drop time according to the detection interval, leading to a prolonged voltage drop time.

[0011] 4. Low power detection accuracy

[0012] While existing technologies take into account the influence of nearby interference signals and use mixers for frequency conversion, they do not consider the calibration of the receiving channel frequency response or the interference of image frequency signals and intermediate frequency signals, resulting in low detection accuracy of power signals. Summary of the Invention

[0013] In order to solve the problems of the shortcomings and defects in the prior art, the present invention provides a power detection module, a multi-mode power detection circuit with variable bandwidth and a receiver system, which can adapt to various modulation methods, realize multi-mode and high-precision power detection, and comprehensively consider the trade-off between power detection time and output noise suppression.

[0014] To achieve the above-mentioned objectives of this invention, the technical solution adopted is as follows:

[0015] A power detection module includes a detector for power detection and a detector peripheral circuit electrically connected to the detector.

[0016] The detector peripheral circuit includes several integrating capacitors with different capacitance values; the integrating capacitors are connected in parallel; and a first selection switch is connected in series in the branch where each integrating capacitor is located.

[0017] Depending on the detection mode, the integrating capacitors of different capacitance values ​​are selected by controlling the on / off state of the first selection switch, thereby adapting to different detection modes.

[0018] Preferably, when the circuit is in fast detection mode, the detector switches from the first branch to the second branch; when the circuit output noise exceeds the first threshold, the detector switches from the third branch to the fourth branch, wherein the capacitance value of the integrating capacitor on the second branch is less than the capacitance value of the integrating capacitor on the first branch; and the capacitance value of the integrating capacitor on the fourth branch is greater than the capacitance value of the integrating capacitor on the fourth branch.

[0019] Preferably, the peripheral circuit of the detector is further provided with a direct branch, which is connected in parallel with several integrating capacitors of different capacitance values;

[0020] A second selector switch is connected in series on the direct branch;

[0021] If the required detection interval is less than t and the capacitor discharge rate is less than v, then the direct-through branch can be switched to allow the capacitor to discharge rapidly, reducing the voltage drop time and adapting to different detection modes.

[0022] A multimode power detection circuit with variable bandwidth includes a gain adjustment module, a filtering module, a mixing module, multiple surface acoustic wave filters with different bandwidths, and the power detection module as described above, connected in sequence.

[0023] The gain adjustment module is used to calibrate the amplitude of input signals at different frequencies.

[0024] The filtering module is used to filter the input signal output by the gain adjustment module to suppress intermediate frequency interference and image interference of the input signal; and input the input signal filtered by the filtering module into the mixer module.

[0025] The aforementioned mixing module is used to shift the input signal operating within the frequency band to a fixed intermediate frequency point; and to input the input signal through the mixing module into multiple surface acoustic wave (SAW) filters with different bandwidths.

[0026] The aforementioned multi-channel surface acoustic wave (SAW) filters with different bandwidths are used to select the corresponding bandwidth SAW filter according to the modulation waveform of the input signal in order to adapt to different modulation waveforms.

[0027] The power detection module is used to detect the power of the input signal output by the surface acoustic wave filter.

[0028] Preferably, the gain adjustment module includes an adjustable gain amplifier and a ROM memory;

[0029] The adjustable gain amplifier uses a lookup table in the ROM memory to calibrate the amplitude of input signals at different frequencies.

[0030] Preferably, the filtering module is a tuned bandpass filter.

[0031] Preferably, the mixing module includes a variable local oscillator and a mixer;

[0032] The mixer is used to receive the input signal output by the filtering module; at the same time, it outputs the input signal through the mixer to the multiple surface acoustic wave filters with different bandwidths.

[0033] The variable local oscillator is electrically connected to the mixer.

[0034] Preferably, a third gating switch is connected in series at both the output and input ends of each surface acoustic wave (SAW) filter; the corresponding SAW filter is selected by controlling the on / off state of the gating switch.

[0035] Preferably, the multiple surface acoustic wave (SAW) filters with different bandwidths are SAW filters with 1dB bandwidths of 1M, 5M, 10M, and 20M, respectively.

[0036] A receiver system includes a bandwidth-variable multimode power detection circuit as described above.

[0037] The beneficial effects of this invention are as follows:

[0038] This invention redesigns the peripheral circuit of the detector, and allows for the selection of branches of integrating capacitors with different capacitance values ​​via a selection switch, based on the required detection time and noise suppression characteristics.

[0039] In the design of the detector's peripheral circuit, the integrating capacitor determines the detection time and the magnitude of the output voltage ripple. Therefore, the selection of the integrating capacitor's value is crucial. This invention employs a first selection switch to select different integrating capacitors for different detection modes, enabling control over the detection time and output voltage noise according to the specific detection mode.

[0040] This invention also proposes a second gating switch to select surface acoustic wave filters with different bandwidths for different input signal modulation waveforms, thereby providing different channel bandwidths and enabling the detection of signals with different bandwidths.

[0041] The multi-mode power detection circuit described in this invention can adapt to various bandwidth modulation methods, offering high power detection accuracy and ease of design. Furthermore, the novel detector peripheral circuitry can control the detection time and output noise, enabling fast detection and low-noise modes. It can also adjust the voltage drop time according to the detection interval to adapt to different detection modes. Attached Figure Description

[0042] Figure 1 This is a schematic diagram of the peripheral circuit of the detector described in this invention.

[0043] Figure 2 This is a block diagram of the multimode power detection circuit described in this invention.

[0044] In the diagram, 1-gain adjustment module, 101-adjustable gain amplifier, 102-ROM memory, 2-filter module, 201-tuned bandpass filter, 3-mixer module, 301-mixer, 302-variable local oscillator, 4-surface acoustic wave filter, 401-third gating switch, 5-power detection module, 501-detector, 502-integrating capacitor, 503-first gating switch, 504-second gating switch. Detailed Implementation

[0045] The present invention will now be described in detail with reference to the accompanying drawings and specific embodiments.

[0046] Example 1

[0047] A power detection module 5 includes a detector 501 for power detection and peripheral circuitry of the detector 501 electrically connected to the detector 501.

[0048] like Figure 1 As shown, the peripheral circuit of the detector 501 includes several integrating capacitors 502 with different capacitance values; the several integrating capacitors 502 are connected in parallel; and a first gating switch 503 is connected in series on the branch where each integrating capacitor 502 is located.

[0049] Depending on the detection mode, the integrating capacitor 502 with different capacitance values ​​can be selected by controlling the on / off state of the first selection switch 503, thereby adapting to different detection modes.

[0050] In this embodiment, the peripheral circuit of the detector 501 is redesigned. Based on the required detection time and noise suppression characteristics, the branches of the integrating capacitor 502 with different capacitance values ​​can be selected by the first selection switch 503.

[0051] In the design of the peripheral circuit of detector 501, the integrating capacitor 502 determines the detection time and the ripple of the output voltage. Therefore, the selection of the capacitance value of the integrating capacitor 502 is crucial. A larger capacitance value results in a larger time constant and a longer power detection time, but also a more complete charging and discharging process, leading to a flatter output voltage for detector 501. Conversely, a smaller capacitance value results in a shorter detection time, but also a larger output voltage ripple. Furthermore, an excessively large capacitance value can affect the time interval between subsequent detections. Currently, the peripheral circuit of detector 501 typically uses a single integrating capacitor 502 with a fixed capacitance value, which is insufficient to meet the detection requirements of various modulation methods.

[0052] Therefore, to adapt to various bandwidth and detection mode requirements, and to balance the detection time and output noise suppression characteristics of detector 501, this embodiment proposes a peripheral circuit design for detector 501. This design allows for the selection of different capacitance values ​​for integrating capacitor 502 circuits using a first selection switch 503, based on different usage requirements. The specific integrating capacitor 502 switching circuit is as follows: Figure 1 As shown.

[0053] In a specific embodiment, when the circuit is in fast detection mode, the detector 501 switches from the first branch to the second branch; when the circuit output noise exceeds the first threshold, the detector 501 switches from the third branch to the fourth branch, wherein the capacitance of the integrating capacitor 502 on the second branch is less than the capacitance of the integrating capacitor 502 on the first branch; the capacitance of the integrating capacitor 502 on the fourth branch is greater than the capacitance of the integrating capacitor 502 on the fourth branch. The circuit output noise generally refers to voltage ripple. The first threshold value ranges from 200 to 300 mVpp, and a typical value is 250 mVpp. When the circuit output noise exceeds the first threshold, a large capacitor needs to be added for filtering.

[0054] In one specific embodiment, the peripheral circuit of the detector 501 is further provided with a direct branch, which is connected in parallel with several integrating capacitors 502 of different capacitance values.

[0055] A second selector switch 504 is connected in series on the direct branch;

[0056] If the required detection interval is less than t and the capacitor discharge rate is less than v, the direct-through branch can be switched to allow the capacitor to discharge rapidly, reducing the voltage drop time and adapting to different detection modes. The required detection interval depends on system requirements; it needs to be considered when the system has no specific requirements for the required detection interval. The specific required interval depends on the system requirements. Generally, t can be selected as 0.1 µs, but the specific value needs to be determined based on the requirements. The capacitor discharge rate v is related to the capacitance, charging voltage, and current.

[0057] In this embodiment, a direct-through branch is added to the peripheral circuit of detector 501. If the required detection interval is short and the capacitor discharge speed is slow, this path can be switched to allow the capacitor to discharge quickly, thereby achieving a faster voltage drop time to adapt to different detection modes.

[0058] Example 2

[0059] To achieve multi-mode broadband and high-precision power detection, this embodiment also proposes a multi-mode power detection circuit with variable bandwidth, such as... Figure 2As shown. Through proper design, the multi-mode power detection circuit can not only suppress interference such as image frequencies and intermediate frequency frequencies outside the useful signal band, but also down-convert the input signal to a fixed intermediate frequency point, thereby improving the accuracy of power detection.

[0060] Specifically, a multimode power detection circuit with variable bandwidth includes a gain adjustment module 1, a filtering module 2, a mixing module 3, multiple surface acoustic wave filters with different bandwidths 4, and a power detection module 5 as described in Example 1, connected in sequence.

[0061] The gain adjustment module 1 is used to perform amplitude calibration on input signals of different frequencies;

[0062] The filtering module 2 is used to filter the input signal output by the gain adjustment module 1 to suppress intermediate frequency interference and image interference of the input signal; and input the input signal filtered by the filtering module 2 into the mixing module 3.

[0063] The mixing module 3 is used to shift the input signal operating within the frequency band to a fixed intermediate frequency point; and to input the input signal through the mixing module 3 into multiple surface acoustic wave (SAW) filters 4 with different bandwidths.

[0064] The aforementioned multi-channel surface acoustic wave (SAW) filter 4 with different bandwidths is used to select the corresponding bandwidth SAW filter 4 according to the modulation waveform of the input signal, so as to adapt to different modulation waveforms.

[0065] The power detection module 5 is used to detect the power of the input signal output by the surface acoustic wave filter 4.

[0066] The power detection module 5 includes a detector 501 for power detection and a peripheral circuit of the detector 501 that is electrically connected to the detector 501.

[0067] The peripheral circuit of the detector 501 includes several integrating capacitors 502 with different capacitance values; the several integrating capacitors 502 are connected in parallel; and a first selection switch 503 is connected in series on the branch where each integrating capacitor 502 is located.

[0068] Depending on the detection mode, the integrating capacitor 502 with different capacitance values ​​can be selected by controlling the on / off state of the first selection switch 503, thereby adapting to different detection modes.

[0069] The aforementioned multimode power detection circuit with variable bandwidth not only fully considers the characteristics of variable bandwidth and variable integrating capacitor 502, which can adapt to various bandwidth modulation methods, but also takes into account the frequency response characteristics of the input signal, ensuring that the detector 501 operates at a fixed frequency point, resulting in high power detection accuracy and ease of design.

[0070] In one specific embodiment, the gain adjustment module 1 includes an adjustable gain amplifier 101 and a ROM memory 102;

[0071] The adjustable gain amplifier 101 uses a lookup table in the ROM memory 102 to perform amplitude calibration on input signals of different frequencies, thereby compensating for frequency response problems in the channel.

[0072] This embodiment addresses the frequency response characteristics of the channel by employing a variable gain amplifier to calibrate the amplitude of signals at different frequencies, which helps improve power detection accuracy.

[0073] In one specific embodiment, the filtering module 2 is a tuned bandpass filter 201. Typically, a tuned bandpass filter 201 is used and placed in front of the power detection module 5 to suppress input intermediate frequency interference and image interference, resulting in a clean input signal.

[0074] This embodiment proposes to suppress input interference signals by using a tuned bandpass filter 201 to suppress image frequency signals and intermediate frequency signals, thereby improving power detection accuracy.

[0075] In one specific embodiment, the mixing module 3 includes a variable local oscillator 302 and a mixer 301;

[0076] The mixer 301 is used to receive the input signal output by the filter module 2; at the same time, it outputs the input signal through the mixer 301 to the multi-channel surface acoustic wave filter 4 with different bandwidths.

[0077] The variable local oscillator 302 is electrically connected to the mixer 301.

[0078] Since the power detection circuit typically operates within a wide frequency band, when the input signal operating within the frequency band passes through the mixer 301, it can be shifted to a fixed intermediate frequency point, thereby improving the accuracy of power detection.

[0079] In one specific embodiment, a third gating switch 401 is connected in series at both the output and input ends of each surface acoustic wave filter 4; the corresponding surface acoustic wave filter 4 is selected by controlling the on / off state of the gating switch.

[0080] In one specific embodiment, the multiple surface acoustic wave (SAW) filters 4 with different bandwidths are SAW filters 4 with 1dB bandwidths of 1M, 5M, 10M, and 20M, respectively.

[0081] This embodiment proposes to use a third gating switch 401 to select surface acoustic wave (SAW) filters 4 with different bandwidths for receiving different modulation signals, thereby providing different channel bandwidths and enabling the detection of signals with different bandwidths.

[0082] To verify the feasibility of the proposed variable bandwidth multimode power detection circuit in this embodiment, a design example is provided. In practice, appropriate components can be selected based on application requirements. In this embodiment, the tuned bandpass filter 201 uses an ADI RMS detector 501ADL5906, and the multiple surface acoustic wave (SAW) filters 4 with different bandwidths employ intermediate frequency (IF) filter banks with 1dB bandwidths of 1MHz, 5MHz, 10MHz, and 20MHz. This circuit can support power detection of different modulation signals, such as QPSK, 64QAM, and WCDMA waveforms. The IF filter path is switched according to different bandwidths, and the detection time, voltage drop time, and output noise are adjusted by switching the path of the integrating capacitor 502 and the direct-through branch. The test parameters for different modulation methods are shown in Table 1.

[0083] Table 1 Test Indicators for Different Modulation Methods

[0084]

[0085] Example 3

[0086] A receiver system includes a multimode power detection circuit with variable bandwidth as described in Embodiment 2, comprising a gain adjustment module 1, a filtering module 2, a mixing module 3, multiple surface acoustic wave filters with different bandwidths 4, and a power detection module 5 as described in Embodiment 1, connected in sequence.

[0087] The gain adjustment module 1 is used to perform amplitude calibration on input signals of different frequencies;

[0088] The filtering module 2 is used to filter the input signal output by the gain adjustment module 1 to suppress intermediate frequency interference and image interference of the input signal; and input the input signal filtered by the filtering module 2 into the mixing module 3.

[0089] The mixing module 3 is used to shift the input signal operating within the frequency band to a fixed intermediate frequency point; and to input the input signal through the mixing module 3 into multiple surface acoustic wave (SAW) filters 4 with different bandwidths.

[0090] The aforementioned multi-channel surface acoustic wave (SAW) filter 4 with different bandwidths is used to select the corresponding bandwidth SAW filter 4 according to the modulation waveform of the input signal, so as to adapt to different modulation waveforms.

[0091] The power detection module 5 is used to detect the power of the input signal output by the surface acoustic wave filter 4.

[0092] The power detection module 5 includes a detector 501 for power detection and a peripheral circuit of the detector 501 that is electrically connected to the detector 501.

[0093] The peripheral circuit of the detector 501 includes several integrating capacitors 502 with different capacitance values; the several integrating capacitors 502 are connected in parallel; and a first selection switch 503 is connected in series on the branch where each integrating capacitor 502 is located.

[0094] Depending on the detection mode, the integrating capacitor 502 with different capacitance values ​​can be selected by controlling the on / off state of the first selection switch 503, thereby adapting to different detection modes.

[0095] The aforementioned multimode power detection circuit with variable bandwidth not only fully considers the characteristics of variable bandwidth and variable integrating capacitor 502, which can adapt to various bandwidth modulation methods, but also takes into account the frequency response characteristics of the input signal, ensuring that the detector 501 operates at a fixed frequency point, resulting in high power detection accuracy and ease of design.

[0096] Obviously, the above embodiments of the present invention are merely examples for clearly illustrating the present invention, and are not intended to limit the implementation of the present invention. Any modifications, equivalent substitutions, and improvements made within the spirit and principles of the present invention should be included within the protection scope of the claims of the present invention.

Claims

1. A bandwidth variable multi-mode power detection circuit, characterized by: It includes a gain adjustment module (1), a filter module (2), a mixer module (3), a multi-channel surface acoustic wave filter with different bandwidths (4), and a power detection module (5) connected in sequence. The gain adjustment module (1) is used to perform amplitude calibration on input signals of different frequencies, and includes an adjustable gain amplifier (101) and a ROM memory (102). The adjustable gain amplifier (101) performs amplitude calibration on input signals of different frequencies through a lookup table in the ROM memory (102); The filtering module (2) is a tuned bandpass filter (201) used to filter the input signal output by the gain adjustment module (1) to suppress the intermediate frequency interference and image interference of the input signal; and input the input signal filtered by the filtering module (2) into the mixing module (3). The mixing module (3) is used to shift the input signal operating within the frequency band to a fixed intermediate frequency point; the input signal through the mixing module (3) is input to multiple surface acoustic wave filters (4) with different bandwidths, including a variable local oscillator (302) and a mixer (301). The mixer (301) is used to receive the input signal output by the filter module (2); at the same time, it outputs the input signal through the mixer (301) to the multiple surface acoustic wave (SAW) filters (4) with different bandwidths. A third gating switch (401) is connected in series at the output and input ends of each SAW filter (4). The multiple SAW filters (4) with different bandwidths are SAW filters (4) with 1dB bandwidths of 1M, 5M, 10M and 20M respectively. The corresponding SAW filter (4) is selected by controlling the on and off of the gating switch. The variable local oscillator (302) is electrically connected to the mixer (301); The aforementioned multi-channel surface acoustic wave filter (4) with different bandwidths is used to select the corresponding bandwidth surface acoustic wave filter (4) according to the modulation waveform of the input signal, so as to adapt to different modulation waveforms. The power detection module (5) is used to detect the power of the input signal output by the surface acoustic wave filter (4), including a detector (501) for power detection and a peripheral circuit of the detector (501) electrically connected to the detector (501). The peripheral circuit of the detector (501) includes several integrating capacitors (502) with different capacitance values; the several integrating capacitors (502) are connected in parallel; and a first gating switch (503) is connected in series on the branch where each integrating capacitor (502) is located. According to different detection modes, the integrating capacitor (502) with different capacitance values ​​is selected by controlling the on and off of the first selection switch (503) to adapt to different detection modes; The detector (501) peripheral circuit is provided with a direct branch, which is connected in parallel with several integrating capacitors (502) of different capacitance values. A second selector switch (504) is connected in series on the direct branch; If the required detection interval is less than t and the capacitor discharge rate is less than v, then the direct-through branch can be switched. When the circuit is in fast detection mode, the detector (501) switches from the first branch to the second branch; when the circuit output noise exceeds the first threshold, the detector (501) switches from the third branch to the fourth branch, wherein the capacitance value of the integrating capacitor (502) on the second branch is less than the capacitance value of the integrating capacitor (502) on the first branch; and the capacitance value of the integrating capacitor (502) on the fourth branch is greater than the capacitance value of the integrating capacitor (502) on the fourth branch.

2. A receiver system, characterized by: Includes the multimode power detection circuit with variable bandwidth as described in claim 1.

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