Superheterodyne transceiver system

Abstract

The invention relates to a superheterodyne transceiver system, which belongs to the technical field of millimeter wave and wireless radio frequency links, and comprises a transmitter and a receiver, the transmitter comprises a plurality of first chopping modulation modules used for modulating a plurality of paths of baseband signals to different intermediate frequency bands through a first chopping circuit to obtain a plurality of paths of different intermediate frequency signals; the first local oscillator source is used for generating a shared up-conversion local oscillator signal; the plurality of first frequency mixing modules are used for performing frequency mixing processing on the plurality of paths of intermediate frequency signals and the up-conversion local oscillator signals respectively so as to perform up-conversion on the intermediate frequency signals to an E wave band and obtain a plurality of paths of E wave band signals; the transmitting module is used for transmitting multiple paths of E-waveband signals; and the receiver is used for receiving the multiple paths of E-band signals and demodulating a target signal from the multiple paths of E-band signals. According to the invention, the demand on a local oscillator source is reduced, so that the complexity, power consumption and cost of the system are reduced.

Description

Technical Field

[0001] This invention relates to the field of millimeter wave and wireless radio frequency link technology, and in particular to a superheterodyne transceiver system. Background Technology

[0002] With the large-scale commercialization of 5G mobile communication technology and the launch of research into 6G communication technology, society's demand for wireless data transmission rates and capacity is experiencing explosive growth. Emerging applications such as high-definition video streaming, virtual reality, the Internet of Things, Industry 4.0, and future integrated space-ground networks are placing stringent demands on communication systems, requiring transmission rates down to the Tbps level and latency down to the millisecond level. The traditional microwave band operating below 6 GHz, due to its increasingly depleted spectrum resources, can no longer meet this demand. Therefore, turning to the millimeter-wave band, with its vast continuous bandwidth, has become an inevitable trend in the development of wireless communication.

[0003] In the millimeter-wave frequency band, the E-band (typically referring to the 71–76 GHz and 81–86 GHz bands) has attracted much attention due to its unique advantages and is hailed as the "golden spectrum of the microwave field." First, the E-band offers a continuous usable bandwidth of up to 10 GHz, which is unattainable by traditional microwave bands, laying the physical foundation for ultra-high-speed data transmission. Second, according to the International Telecommunication Union's allocation, this band is dedicated to fixed wireless communication, resulting in a clean spectrum with less interference. Furthermore, the E-band lies within the millimeter-wave atmospheric attenuation window, resulting in relatively low transmission loss (approximately 0.5 dB / km), making line-of-sight transmission over distances of several kilometers possible.

[0004] Despite the promising future of the E-band, its technological implementation faces significant challenges. In systems supporting multi-channel broadband transmission, traditional systems achieve two frequency conversions by mixing with the local oscillator signal. Since each channel has a different frequency, different local oscillator signals are needed to convert to the same baseband. Furthermore, referring to… Figure 1 Traditional systems typically require a separate local oscillator (LO) for each channel for mixing, which significantly increases system complexity, power consumption, and cost, and also introduces phase noise and frequency synchronization issues among multiple LOs. Therefore, designing a compact solution that supports multi-channel transmission without relying on multiple LOs for the high-frequency, wideband application scenario of the E-band has become a critical technical problem urgently needing to be solved in the current millimeter-wave communication field. Summary of the Invention

[0005] In view of this, it is necessary to provide a superheterodyne transceiver system to solve the problems of phase noise and frequency synchronization between multiple local oscillators caused by the introduction of multiple local oscillators in existing E-band signal communication systems.

[0006] To address the aforementioned problems, in a first aspect, the present invention provides a superheterodyne transceiver system, comprising: Transmitter and receiver; among which, The transmitter includes: Multiple first chopper modulation modules are used to modulate multiple baseband signals onto different intermediate frequency bands through a first chopper circuit to obtain multiple different intermediate frequency signals; The first local oscillator source is used to generate a shared up-conversion local oscillator signal; Multiple first mixing modules are used to mix the multiple intermediate frequency signals with the up-converted local oscillator signal respectively, so as to up-convert the intermediate frequency signal to the E-band and obtain multiple E-band signals; The transmitting module is used to transmit the multiple E-band signals; The receiver is used to receive the multiple E-band signals and demodulate the target signal from the multiple E-band signals.

[0007] In one possible implementation, the receiver includes: The receiving module is used to receive the multiple E-band signals; The second local oscillator source is used to generate the shared down-conversion local oscillator signal; Multiple second mixing modules are used to mix the multiple E-band signals with the down-converted local oscillator signal respectively, so as to down-convert the multiple E-band signals to the intermediate frequency band to obtain multiple intermediate frequency signals; Multiple second chopper modulation modules are used to demodulate the multiple intermediate frequency signals through a second chopper circuit to obtain the target signal.

[0008] In one possible implementation, the target signal is a low-intermediate frequency signal; the plurality of first chopper modulation modules are used to generate multiple first square wave signals with different frequencies and frequency intervals greater than one baseband bandwidth through a first chopper circuit, and to modulate the multiple baseband signals to different intermediate frequency bands through the first square wave signals. The plurality of second chopper modulation modules are used to generate multiple target frequency second square wave signals through the second chopper circuit, and demodulate the multiple intermediate frequency signals to the same low intermediate frequency signal through the second square wave signals; wherein, the target frequency of each channel is the absolute value of the difference between the frequency of each intermediate frequency signal and the frequency of the low intermediate frequency signal.

[0009] In one possible implementation, the frequencies of both the first square wave signal and the second square wave signal are less than 1 GHz.

[0010] In one possible implementation, each of the first chopper circuit and the second chopper circuit includes a chopper and a low-pass filter.

[0011] In one possible implementation, the target signal is a low-intermediate frequency signal, and the receiver further includes: Multiple automatic gain amplifier and filter modules are used to determine the gain of each variable gain amplifier based on the power of each low-IF signal, amplify each low-IF signal through the variable gain amplifier, and perform low-pass filtering on the amplified low-IF signal through a low-pass filter.

[0012] In one possible implementation, the receiver further includes: Multiple baseband modules are used to suppress the image frequency in the low-intermediate frequency signal after low-pass filtering via a Hartley structure.

[0013] In one possible implementation, the first mixing module includes an orthogonal mixer and a bandpass filter; the first mixing module is used to mix multiple intermediate frequency signals with the up-converted local oscillator signal respectively through the orthogonal mixer, and to perform bandpass filtering on the multiple E-band signals obtained by mixing through the bandpass filter.

[0014] In one possible implementation, the second mixing module includes a quadrature mixer for mixing the multiple E-band signals with the down-converted local oscillator signal via the quadrature mixer.

[0015] In one possible implementation, the transmitting module includes: A power combiner is used to combine the multiple E-band signals into a single radio frequency signal. A power amplifier for amplifying the power of the radio frequency signal; A transmitting antenna is used to radiate the amplified radio frequency signal outwards. The receiving module includes: A receiving antenna for receiving radio frequency signals radiated by the transmitting antenna; A low-noise amplifier is used to amplify received radio frequency signals; A multiplexer is used to separate the amplified radio frequency signal into multiple E-band signals.

[0016] In one possible implementation, the power combiner and the multiplexer are structurally symmetrical.

[0017] The beneficial effects of this invention are: Traditional superheterodyne structures achieve two frequency conversions by mixing with the local oscillator signal. In this invention, however, using a first chopper modulation module to modulate the baseband signal effectively replaces one frequency conversion in the superheterodyne, reducing the number of local oscillator sources. Furthermore, in the second frequency conversion, this invention generates a shared up-converted local oscillator signal using the first local oscillator source. This shared up-converted local oscillator signal is then used to uniformly convert the intermediate frequency signal output from the first chopper modulation module, resulting in an E-band signal. Compared to the traditional method of configuring an independent local oscillator source for each channel, this further reduces the number of local oscillator sources. In summary, this invention reduces system complexity, power consumption, and cost, and avoids phase noise and frequency synchronization problems between multiple local oscillators at the receiver. Attached Figure Description

[0018] To more clearly illustrate the technical solutions in the embodiments of the present invention, the accompanying drawings used in the description of the embodiments will be briefly introduced below. Obviously, the accompanying drawings described below are only some embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0019] Figure 1 This is a schematic diagram of a traditional multi-channel broadband transmission system according to one embodiment. Figure 2 A schematic diagram of a structure of an embodiment of the superheterodyne transceiver system provided by the present invention; Figure 3 This is a schematic diagram of a chopper topology; Figure 4 This is a schematic diagram of image frequency interference. Detailed Implementation

[0020] The technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only a part of the embodiments of the present invention, and not all of them. All other embodiments obtained by those skilled in the art based on the embodiments of the present invention without creative effort are within the scope of protection of the present invention.

[0021] In the description of the embodiments of this invention, unless otherwise stated, "a plurality of" means two or more. The terms "first," "second," etc., used in the embodiments of this invention are used to distinguish similar objects, and are not used to describe a specific order or sequence, nor to indicate or imply their relative importance or implicitly specify the number of indicated technical features. It should be understood that such data can be interchanged where appropriate so that embodiments of this application can be implemented in orders other than those illustrated or described herein, and the objects distinguished by "first," "second," etc., are generally of the same class, and the number of objects is not limited; for example, a first object can be one or more.

[0022] In this document, the term "embodiment" means that a particular feature, structure, or characteristic described in connection with an embodiment may be included in at least one embodiment of the invention. The appearance of this phrase in various places throughout the specification does not necessarily refer to the same embodiment, nor is it a separate or alternative embodiment mutually exclusive with other embodiments. It will be explicitly and implicitly understood by those skilled in the art that the embodiments described herein can be combined with other embodiments.

[0023] Reference Figure 2 The diagram illustrates a structural schematic of an embodiment of the superheterodyne transceiver system provided by the present invention. The system 10 includes: Transmitter 100 and receiver 200; wherein, Transmitter 100 includes: Multiple first chopper modulation modules 110 are used to modulate multiple baseband signals to different intermediate frequency bands through a first chopper circuit to obtain multiple different intermediate frequency signals; The first local oscillator source 120 is used to generate a shared up-conversion local oscillator signal; Multiple first mixing modules 130 are used to mix multiple intermediate frequency signals with up-converted local oscillator signals respectively, so as to up-convert the intermediate frequency signals to the E-band and obtain multiple E-band signals. Transmitting module 140 is used to transmit multiple E-band signals; Receiver 200 is used to receive multiple E-band signals and demodulate the target signal from the multiple E-band signals.

[0024] Specifically, at transmitter 100, multiple parallel channels with the same bandwidth (all...) are... b The baseband signal is first processed by multiple independent first chopper modulation modules 110. Each baseband signal is modulated by a specific chopper frequency, shifting its spectrum to a different intermediate frequency band, and the spectra of these modulated signals do not overlap in the frequency domain. Subsequently, these spectrum-shifted intermediate frequency signals are combined with a shared high-performance up-conversion local oscillator signal. The signals are input together into the first mixer module 130 and upconverted to the E-band (71-76 GHz / 81-86 GHz). Finally, the multiple E-band signals obtained from the upconversion are radiated into free space through the transmitter module 140.

[0025] For example, a superheterodyne transceiver system has three channels, and its transmitter-side processing flow is as follows: the bandwidth of each of the three baseband signals is 200 MHz, and the local oscillator signal... The local oscillator frequency is set to 72.1 GHz. The chopper in the first chopper modulation module of the first channel is in the off state, and its output signal center frequency remains at 0 Hz (i.e., baseband). The second and third choppers operate at chopping frequencies of 300 MHz and 600 MHz, respectively. After modulation and subsequent low-pass filtering, their signal spectra are shifted to center frequencies of 300 MHz and 600 MHz, respectively. Subsequently, the three intermediate frequency signals (center frequencies of 0 Hz, 300 MHz, and 600 MHz, respectively) are up-converted by the same 72.1 GHz local oscillator signal, and finally synthesized into an E-band signal covering the frequency band from 72 GHz to 72.7 GHz, which is then radiated through the antenna.

[0026] At receiver 200, multiple E-band signals are received and processed through down-conversion, demodulation, and filtering to obtain the target signal. The target signal can be a low-IF signal or a baseband signal.

[0027] Traditional superheterodyne structures achieve two frequency conversions by mixing with the local oscillator signal. In this invention, however, using a first chopper modulation module to modulate the baseband signal effectively replaces one frequency conversion in the superheterodyne, reducing the number of local oscillator sources. Furthermore, in the second frequency conversion, this invention generates a shared up-converted local oscillator signal using the first local oscillator source. This shared up-converted local oscillator signal is then used to uniformly convert the intermediate frequency signal output from the first chopper modulation module, resulting in an E-band signal. Compared to the traditional method of configuring an independent local oscillator source for each channel, this further reduces the number of local oscillator sources. In summary, this invention reduces system complexity, power consumption, and cost, while avoiding phase noise and frequency synchronization problems between multiple local oscillators.

[0028] In some embodiments of the present invention, the receiver 200 includes: Receiver module 210 is used to receive multiple E-band signals; The second local oscillator 220 is used to generate a shared down-conversion local oscillator signal; Multiple second mixing modules 230 are used to mix multiple E-band signals with down-converted local oscillator signals respectively, so as to down-convert multiple E-band signals to intermediate frequency band to obtain multiple intermediate frequency signals; Multiple second chopper modulation modules 240 are used to demodulate multiple intermediate frequency signals through a second chopper circuit to obtain the target signal.

[0029] At receiver 200, the multiple E-band signals received by receiver module 210 enter the corresponding second mixing module 230. Multiple second mixing modules 230 down-convert the multiple E-band signals to an intermediate frequency (IF) based on a shared down-conversion local oscillator signal. Each IF signal enters the corresponding second chopper modulation module 240, which uses a preset chopper frequency to shift its spectrum to a unified frequency signal, thus obtaining the target signal.

[0030] For example, continuing the above example, the receiver-side processing flow corresponds to the transmitter-side: the receiver-side local oscillator frequency is set to 72 GHz. The receiver module 210 receives three E-band signals from 72 GHz to 72.7 GHz, and then down-converts them with the 72 GHz local oscillator signal to obtain a 0 Hz to 700 MHz intermediate frequency broadband signal. The chopper in the second chopper modulation module of the first channel is turned off, and the signal is passed directly; the second and third channels are demodulated using chopper frequencies of 200 MHz and 500 MHz respectively. This process uniformly shifts the three intermediate frequency signals with different center frequencies to a low intermediate frequency of 100 MHz, thus obtaining the target signal.

[0031] In summary, this embodiment adopts a symmetrical design at the receiver end as at the transmitter end. Therefore, the number of local oscillators required at the receiver end can be reduced synchronously, further simplifying the system complexity, reducing system power consumption and cost, and avoiding phase noise and frequency synchronization problems among multiple local oscillators at the receiver end.

[0032] In some embodiments of the present invention, the target signal is a low-intermediate frequency signal; a plurality of first chopper modulation modules 110 are used to generate multiple first square wave signals with different frequencies and frequency intervals greater than one baseband bandwidth through a first chopper circuit, and to modulate the multiple baseband signals to different intermediate frequency bands through the first square wave signals. Multiple second chopper modulation modules are used to generate multiple target frequency second square wave signals through a second chopper circuit, and to demodulate multiple intermediate frequency signals to the same low intermediate frequency signal through the second square wave signals; wherein, the target frequency of each channel is the absolute value of the difference between the frequency of each intermediate frequency signal and the frequency of the low intermediate frequency signal.

[0033] Specifically, a low-IF signal refers to the relatively low-frequency portion of an intermediate frequency (IF) signal, a IF signal close to DC but not zero (typically several hundred kHz to several MHz). Directly converting to zero IF would result in DC offset and flicker noise issues. These problems are amplified dramatically in wideband, high-sensitivity E-band communication, severely degrading the system's signal-to-noise ratio and modulation quality, thus limiting its performance in high-order modulation applications. Therefore, in this embodiment, the IF signal is down-converted to a low-IF rather than zero IF at the receiver, effectively avoiding the DC offset and flicker noise problems associated with zero IF.

[0034] Chopping is a continuous-time modulation technique that transforms signals through modulation and demodulation. The chopper, the core circuit for this technique, consists of a series of controlled switches used to generate a square wave signal at a specific frequency (the chopping frequency). When a signal passes through the chopper, in the frequency domain, this is equivalent to convolving the signal's spectrum with the square wave signal's spectrum. According to the Fourier transform principle, this convolution operation copies and shifts the input signal's spectrum to the odd harmonic points of the chopping frequency. Subsequently, by passing through a low-pass filter, the target signal successfully shifted to the chopping fundamental frequency can be extracted.

[0035] Chopping frequency configuration scheme for transmitter 100: A specific chopping frequency is assigned to each of the N parallel baseband signals. This chopping frequency is used to shift the spectrum of each baseband signal to a different intermediate frequency band, and the shifted signal spectra do not overlap in the frequency domain. Chopper frequency configuration scheme for receiver 200: A specific chopping frequency is assigned to each of the N intermediate frequency signals after downconversion from the second mixer module. This chopping frequency is used to shift the spectrum of the N intermediate frequency signals with different center frequencies to a unified low intermediate frequency.

[0036] The frequency configuration scheme will continue to be referenced. Figure 2 First chopper circuit frequency configuration: ,in, It is the first i The frequency of the first chopper circuit. No. j The frequency of the first chopper circuit. b This refers to the baseband signal bandwidth. The second chopper circuit's frequency configuration is as follows: ,in, It is the first i The frequency of the second chopper circuit. It is the first one received i The intermediate frequency of the road, It is a unified low-to-mid frequency.

[0037] In summary, this embodiment uses a first chopper modulation module to shift the baseband signal to different intermediate frequency bands, and a second chopper modulation module to shift different intermediate frequency signals to a unified low intermediate frequency information. The chopper modulation module enables flexible shifting of signal frequencies. Furthermore, a shared local oscillator signal is used to achieve another unified shift of signals, thereby realizing communication based on E-band signals while reducing the local oscillator source of the system.

[0038] In some embodiments of the present invention, each of the first chopper circuit and the second chopper circuit includes a chopper and a low-pass filter (LPF).

[0039] Continue to refer to Figure 2 Along the signal transmission direction, in the first chopper circuit, an LPF is connected after the chopper; that is, the chopper output signal enters the LPF, and the LPF output signal enters the first mixer module 130. In the second chopper circuit, an LPF is connected before and after the chopper.

[0040] Reference Figure 3 The diagram illustrates a chopper topology. The circuit consists of a full-bridge structure formed by four switches (S1, S2, S3, S4) and two complementary square wave signals. and To perform control. Its basic working principle is that when For high level When the signal is low, switches S1 and S4 are on, and S2 and S3 are off, allowing the input signal to pass through the load along a single path; in the next half-cycle, when... It becomes low level and When the signal goes high, S2 and S3 are turned on, while S1 and S4 are turned off, and the input signal passes through the load with opposite polarity. This cycle repeats, modulating a DC or low-frequency input signal to a frequency that is... The same AC square wave signal.

[0041] The main advantages of this topology lie in its extremely high power efficiency and excellent linearity. Since the switching devices ideally operate in a purely on or off state, their power consumption is very low. More importantly, this structure achieves signal switching and polarity reversal rather than amplification, thus introducing almost no nonlinear distortion and perfectly preserving the original characteristics of the signal.

[0042] In some embodiments of the present invention, the frequencies of both the first square wave signal and the second square wave signal are less than 1 GHz.

[0043] The E-band (71–86 GHz) operates at extremely high frequencies, placing extremely high demands on device performance (such as mixers, filters, and local oscillator phase noise). The chopper used in this invention operates at frequencies below 1 GHz. At the transmitting end, the chopper shifts the baseband signal spectrum to 0-1 GHz; for signals with even narrower bandwidths, it's not necessary to shift it to almost 1 GHz. At the receiving end, the chopper also shifts the 0-1 GHz signal to a low intermediate frequency. Using ultra-high-speed transistors, 1 GHz is easily achievable.

[0044] In some embodiments of the present invention, the receiver 200 further includes: Multiple automatic gain amplifier and filter modules are used to determine the gain of the variable gain amplifier based on the power of each low-IF signal, amplify each low-IF signal through the variable gain amplifier, and perform low-pass filtering on the amplified low-IF signal through the low-pass filter.

[0045] Specifically, the module generates a pulse width modulation signal based on the power of the low-intermediate frequency signal. The pulse width modulation signal is then converted into an analog DC control voltage through low-pass filtering and amplification. The analog DC control voltage is used to control the gain of the variable gain amplifier, thereby achieving high-precision, large dynamic range automatic gain adjustment to stabilize the signal power within the preset range. Finally, the signal passes through a low-pass filter to remove out-of-band noise.

[0046] Because the target signal is a low-to-intermediate frequency signal, its frequency is too close to its image frequency, necessitating a high-Q filter to remove image frequency interference. Figure 4 As shown, Figure 4 Chinese f c It is the desired signal frequency, f LO This is the local oscillator signal frequency. When transmitting a series of broadband signals with similar frequencies, image frequency interference is a problem that cannot be ignored.

[0047] Therefore, in some embodiments of the present invention, the receiver 200 further includes: Multiple baseband modules are used to suppress image frequencies in the low-intermediate frequency signal after low-pass filtering via the Hartley structure.

[0048] The principle of image frequency suppression is as follows: Assume the in-phase component of the input signal is ;in, It is the in-phase component of the input signal. It is the expected signal amplitude. It is the amplitude of the mirror signal. It is the desired signal angular frequency. It is the angular frequency of the image signal. The quadrature component is... ;in, These are the orthogonal components of the input signal, where the first term represents the useful channel and the second term is the mirror signal. Without loss of generality, we can assume low-sideband injection: . It is the angular frequency of the local oscillator signal.

[0049] Input signal Multiplying by the two quadrature signals of LO and ignoring high-frequency components yields the signals for the I and Q paths, respectively: ; ; in, It is the I-channel output signal. It is the Q-channel output signal; The above formula can be further written as: ; ; Then, shift the I-path phase by 90°, and you can get: ; in, It is the signal obtained after phase shifting the I-path by 90°; Then, the phase-shifted I-path and Q-path are added together, and the result at the output is... Signal:

[0050] It can be observed that the image frequency is canceled out and the desired frequency is enhanced, thus suppressing image interference.

[0051] In some embodiments of the present invention, the baseband module in the receiver 200 is also used to convert the processed low-intermediate frequency signal into a digital signal to restore the original data.

[0052] In some embodiments of the present invention, the transmitter 100 further includes: Multiple baseband modules are used to generate multiple parallel baseband signals with the same bandwidth.

[0053] In some embodiments of the present invention, the first mixing module 130 includes an orthogonal mixer and a band-pass filter (BPF); the first mixing module 130 is used to mix multiple intermediate frequency signals with up-converted local oscillator signals respectively through the orthogonal mixer, and to perform band-pass filtering on the multiple E-band signals obtained by mixing through the band-pass filter.

[0054] Specifically, the baseband signal consists of four orthogonal differential signals. After passing through a balun, it can be converted into two orthogonal signals, namely I-channel and I-channel II-channel III ... Q Road The local oscillator signal is used to generate two orthogonal local oscillator signals, namely I local oscillator signals, through a 90° phase shifter in the quadrature mixer. Q-Road Oscillation ; I-channel mixer output ; Q-channel mixer output ; To simplify the calculation, we assume that the baseband signal is a single-frequency signal, i.e. ; .

[0055] Then I-channel mixer output ; Q-channel mixer output ; After passing through the adder in the quadrature mixer: ; ; Achieve up-conversion.

[0056] In some embodiments of the present invention, the second mixing module 230 includes a quadrature mixer for mixing multiple E-band signals with down-converted local oscillator signals respectively through the quadrature mixer.

[0057] In some embodiments of the present invention, the transmitting module 140 includes: A power combiner is used to combine multiple E-band signals into a single radio frequency signal. A power amplifier (PA) is used to amplify the power of radio frequency signals. A transmitting antenna is used to radiate the amplified radio frequency signal outwards. Receiver module 210, including: A receiving antenna, used to receive radio frequency signals radiated by a transmitting antenna; A low-noise amplifier (LNA) is used to amplify received radio frequency signals; A multiplexer is used to separate an amplified radio frequency signal into multiple E-band signals.

[0058] In some embodiments of the present invention, the power combiner and multiplexer are symmetrically structured. The power combiner combines multiple radio frequency signals of different frequencies into a single broadband radio frequency signal for transmission; the multiplexer separates a single broadband radio frequency signal containing multiple frequency bands into multiple radio frequency signals of different frequencies.

[0059] In some embodiments of the present invention, the receiving radio frequency front end, the signal processing part of the receiver, each local oscillator source and power supply module are all integrated on a multilayer printed circuit board to achieve a fully integrated planar layout, and a metal shielding cavity is provided to suppress electromagnetic interference.

[0060] Continue to refer to Figure 2 In the system of this invention, from the transmitter's perspective: Multiple baseband signal sources: This is the starting point of the system. The block diagram shows multiple parallel signal sources, each representing an independent data stream to be transmitted, and their bandwidth is b.

[0061] Chopper circuit: A chopper circuit consists of a chopper and a low-pass filter, used to shift the spectrum of multiple baseband signals with the same bandwidth to different intermediate frequency bands.

[0062] Mixer: Each baseband signal enters an independent mixer. The function of the mixer is spectrum shifting. It mixes the low-frequency baseband signal with a high-frequency local oscillator signal. The signal is mixed; each channel uses the same local oscillator frequency. After mixing, the center frequency of the signal is shifted to the vicinity of the corresponding local oscillator frequency, generating an radio frequency signal.

[0063] Power combiner: The up-converted multiple RF signals are fed into the power combiner; its function is similar to a "reverse splitter," combining multiple signals into a single broadband signal. This combined signal contains information from all the original baseband signals, but each occupies a different frequency band.

[0064] Power amplifier: The power synthesized radio frequency broadband signal by the power combiner has relatively low power and cannot be transmitted wirelessly over long distances; the power amplifier is responsible for significantly increasing the power of this broadband signal to provide sufficient energy.

[0065] Transmitting antenna: Finally, the amplified high-frequency electrical signal is converted into electromagnetic waves by the antenna and radiated into free space; the operating frequency band is the E-band (usually referring to millimeter wave bands such as 71-76 GHz, 81-86 GHz, etc.), which has the advantages of large bandwidth and high transmission rate.

[0066] From the receiver's perspective: The receiver's task is the exact opposite of the transmitter's: it captures weak wireless signals, separates them, and restores them to the original multi-channel baseband signals.

[0067] Receiving antenna: The antenna receives extremely weak E-band electromagnetic wave signals transmitted from the air and converts them into weak electrical signals.

[0068] Low-noise amplifier: The received radio frequency signal is weak and mixed with various noises. The low-noise amplifier is a key component of the receiver. Its main task is to amplify the signal as much as possible while generating extremely low additional noise itself.

[0069] According to Fris's formula Where NF is the system noise figure, NFn is the noise figure of the nth stage amplifier circuit in the system, and Gn 1 represents the gain of the (n-1)th stage amplifier in the circuit. Therefore, the noise figure of the low-noise amplifier determines the signal-to-noise ratio performance of the entire receiving system.

[0070] Multiplexer: The broadband radio frequency signal is fed into the multiplexer; its function is the opposite of the synthesizer at the transmitting end, splitting one signal into multiple radio frequency signals with different center frequencies, which are then sent to multiple subsequent parallel processing channels.

[0071] Mixer and Bandpass Filter: Each branch channel contains a mixer and a bandpass filter. The mixer performs spectrum shifting, down-converting the broadband RF signal to an intermediate frequency (IF) broadband signal. The down-converted signal contains some high-frequency spurious components in addition to the desired IF signal. The bandpass filter's function is to filter out these high-frequency components, allowing only the pure IF signal to pass through.

[0072] Chopper circuit: A chopper circuit consists of a chopper and a bandpass filter, used to shift the spectrum of an intermediate frequency signal to the same low intermediate frequency.

[0073] The recovered baseband signal: After filtering, it undergoes digital signal processing by the baseband module to remove image interference frequencies. Each channel outputs a clean baseband signal, which is consistent with the signal emitted by the corresponding baseband signal source at the transmitting end. At this point, the entire transmission process is complete.

[0074] This signal transmission structure efficiently utilizes the large bandwidth of the E-band to achieve simultaneous transmission of multiple signals. Simultaneously, both the transmitting and receiving ends employ a parallel architecture, resulting in a clear structure that is easy to expand. Furthermore, the addition of a chopper circuit saves on the system's local oscillator, facilitating system integration and miniaturization. Additionally, the receiver can be viewed as the reverse process of the transmitter, with the two being highly symmetrical in structure. Moreover, the utilization of the large bandwidth of the millimeter-wave band makes it ideal for high-speed wireless communication applications, such as wireless base station fronthaul and point-to-point high-speed links.

[0075] Those skilled in the art will understand that all or part of the processes of the methods described in the above embodiments can be implemented by a computer program instructing related hardware, and the program can be stored in a computer-readable storage medium. The computer-readable storage medium may be a disk, optical disk, read-only memory, or random access memory, etc.

[0076] The above description is only a preferred embodiment of the present invention, but the scope of protection of the present invention is not limited thereto. Any changes or substitutions that can be easily conceived by those skilled in the art within the scope of the technology disclosed in the present invention should be included within the scope of protection of the present invention.

Claims

1. A superheterodyne transceiver system, characterized in that, include: Transmitter and receiver; among which, The transmitter includes: Multiple first chopper modulation modules are used to modulate multiple baseband signals onto different intermediate frequency bands through a first chopper circuit to obtain multiple different intermediate frequency signals; The first local oscillator source is used to generate a shared up-conversion local oscillator signal; Multiple first mixing modules are used to mix the multiple intermediate frequency signals with the up-converted local oscillator signal respectively, so as to up-convert the intermediate frequency signal to the E-band and obtain multiple E-band signals; The transmitting module is used to transmit the multiple E-band signals; The receiver is used to receive the multiple E-band signals and demodulate the target signal from the multiple E-band signals.

2. The superheterodyne transceiver system according to claim 1, characterized in that, The receiver includes: The receiving module is used to receive the multiple E-band signals; The second local oscillator source is used to generate the shared down-conversion local oscillator signal; Multiple second mixing modules are used to mix the multiple E-band signals with the down-converted local oscillator signal respectively, so as to down-convert the multiple E-band signals to the intermediate frequency band to obtain multiple intermediate frequency signals; Multiple second chopper modulation modules are used to demodulate the multiple intermediate frequency signals through a second chopper circuit to obtain the target signal.

3. The superheterodyne transceiver system according to claim 2, characterized in that, The target signal is a low-intermediate frequency signal; the plurality of first chopper modulation modules are used to generate multiple first square wave signals with different frequencies and frequency intervals greater than one baseband bandwidth through the first chopper circuit, and to modulate the multiple baseband signals to different intermediate frequency bands through the first square wave signals. The plurality of second chopper modulation modules are used to generate multiple target frequency second square wave signals through the second chopper circuit, and demodulate the multiple intermediate frequency signals to the same low intermediate frequency signal through the second square wave signals; wherein, the target frequency of each channel is the absolute value of the difference between the frequency of each intermediate frequency signal and the frequency of the low intermediate frequency signal.

4. The superheterodyne transceiver system according to claim 3, characterized in that, The frequencies of both the first square wave signal and the second square wave signal are less than 1 GHz.

5. The superheterodyne transceiver system according to claim 3, characterized in that, Each of the first chopper circuit and the second chopper circuit includes a chopper and a low-pass filter.

6. The superheterodyne transceiver system according to claim 2, characterized in that, The target signal is a low-intermediate frequency signal, and the receiver further includes: Multiple automatic gain amplifier and filter modules are used to determine the gain of each variable gain amplifier based on the power of each low-IF signal, amplify each low-IF signal through the variable gain amplifier, and perform low-pass filtering on the amplified low-IF signal through a low-pass filter.

7. The superheterodyne transceiver system according to claim 6, characterized in that, The receiver also includes: Multiple baseband modules are used to suppress the image frequency in the low-intermediate frequency signal after low-pass filtering via a Hartley structure.

8. The superheterodyne transceiver system according to claim 1, characterized in that, The first mixing module includes an orthogonal mixer and a bandpass filter; the first mixing module is used to mix multiple intermediate frequency signals with the up-converted local oscillator signal through the orthogonal mixer, and to perform bandpass filtering on the multiple E-band signals obtained by mixing through the bandpass filter.

9. The superheterodyne transceiver system according to claim 2, characterized in that, The second mixing module includes a quadrature mixer, used to mix the multiple E-band signals with the down-converted local oscillator signal respectively through the quadrature mixer.

10. The superheterodyne transceiver system according to claim 1, characterized in that, The transmitting module includes: A power combiner is used to combine the multiple E-band signals into a single radio frequency signal. A power amplifier for amplifying the power of the radio frequency signal; A transmitting antenna is used to radiate the amplified radio frequency signal outwards. The receiving module includes: A receiving antenna for receiving the radio frequency signal radiated by the transmitting antenna; A low-noise amplifier is used to amplify received radio frequency signals; A multiplexer is used to separate the amplified radio frequency signal into multiple E-band signals.

Images