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Article List
2025, 23(1):12-18.
DOI: 10.11805/TKYDA2024388
Abstract:
A Power Amplifier(PA) module operating in the D-band has been developed. The design includes a Radio Frequency(RF) input/output transition structure and a Direct Current(DC) voltage regulation timing circuit. The RF input/output transition structure utilizes a waveguide-coplanar waveguide transition based on wedge-shaped waveguide film, achieving co-directional conversion and reducing the impact of the gap between the power amplifier chip and the cavity on module performance through a gold wire bonding method similar to coplanar waveguides. The drain bias circuit enhances the stability of the DC voltage regulation timing circuit by paralleling two voltage regulation chips. The design of the choke slot structure effectively reduces the transmission loss when modules are cascaded.Test results indicate that the module has a small-signal gain greater than 10 dB and a maximum gain greater than 17 dB within the 144~166 GHz range; the output power is greater than 27 dBm, with a maximum output power greater than 31 dBm.
A Power Amplifier(PA) module operating in the D-band has been developed. The design includes a Radio Frequency(RF) input/output transition structure and a Direct Current(DC) voltage regulation timing circuit. The RF input/output transition structure utilizes a waveguide-coplanar waveguide transition based on wedge-shaped waveguide film, achieving co-directional conversion and reducing the impact of the gap between the power amplifier chip and the cavity on module performance through a gold wire bonding method similar to coplanar waveguides. The drain bias circuit enhances the stability of the DC voltage regulation timing circuit by paralleling two voltage regulation chips. The design of the choke slot structure effectively reduces the transmission loss when modules are cascaded.Test results indicate that the module has a small-signal gain greater than 10 dB and a maximum gain greater than 17 dB within the 144~166 GHz range; the output power is greater than 27 dBm, with a maximum output power greater than 31 dBm.
2025, 23(1):19-23.
DOI: 10.11805/TKYDA2024536
Abstract:
A novel low phase noise frequency synthesis scheme based on Radio Frequency-In-Package(RF IP) is proposed. The multiple frequency points are generated by the comb generator, the frequency band is selected by the switching filter, and the frequency spectrum shifting is performed by the secondary mixing, therefore, the broadband coverage of Ka-band is realized. The integration method of three-dimensional System-In Package(3D-SIP) compensates for the disadvantage of traditional direct frequency synthesis in achieving miniaturization. A small step variation of 100 MHz is achieved through a frequency divider and multiplier. This scheme can achieve a phase noise of -99 dBc/Hz@1 kHz, compensating for the disadvantage of Direct Digital frequency Synthesis(DDS) excited Phase-Locked Loop(PLL) small step frequency synthesis in achieving low phase noise. This frequency synthesizer has the advantages of miniaturization and low phase noise, has strong engineering application value, and can be expanded for use in various communication and radar systems.
A novel low phase noise frequency synthesis scheme based on Radio Frequency-In-Package(RF IP) is proposed. The multiple frequency points are generated by the comb generator, the frequency band is selected by the switching filter, and the frequency spectrum shifting is performed by the secondary mixing, therefore, the broadband coverage of Ka-band is realized. The integration method of three-dimensional System-In Package(3D-SIP) compensates for the disadvantage of traditional direct frequency synthesis in achieving miniaturization. A small step variation of 100 MHz is achieved through a frequency divider and multiplier. This scheme can achieve a phase noise of -99 dBc/Hz@1 kHz, compensating for the disadvantage of Direct Digital frequency Synthesis(DDS) excited Phase-Locked Loop(PLL) small step frequency synthesis in achieving low phase noise. This frequency synthesizer has the advantages of miniaturization and low phase noise, has strong engineering application value, and can be expanded for use in various communication and radar systems.
2025, 23(1):6-11.
DOI: 10.11805/TKYDA2024393
Abstract:
The electromagnetic losses of nickel waveguides in the submillimeter wave frequency band are measured, and a waveguide terminator based on nickel Spoof Surface Plasmon Polaritons(SSPPs) is designed for multi-port waveguide device measurements and power divider port isolation. The waveguide employs a simple and compact antisymmetric rectangular probe structure to efficiently couple electromagnetic energy from the waveguide to a microstrip, which is then transmitted to a comb-like SSPPs terminator. The microstrip circuit and SSPPs circuit are fabricated on a quartz substrate, with the metal circuit being electroplated metal nickel. Utilizing the band-stop characteristics of SSPPs and the high-frequency high-loss properties of metal nickel, the attenuation and absorption of electromagnetic energy are achieved. The proposed nickel SSPPs waveguide terminator is experimentally validated in the W-band(75~110 GHz). The experimental results indicate that the Return Loss of this waveguide terminator exceeds 15 dB across the entire W-band, with a corresponding electromagnetic absorption rate of over 96.8%.
The electromagnetic losses of nickel waveguides in the submillimeter wave frequency band are measured, and a waveguide terminator based on nickel Spoof Surface Plasmon Polaritons(SSPPs) is designed for multi-port waveguide device measurements and power divider port isolation. The waveguide employs a simple and compact antisymmetric rectangular probe structure to efficiently couple electromagnetic energy from the waveguide to a microstrip, which is then transmitted to a comb-like SSPPs terminator. The microstrip circuit and SSPPs circuit are fabricated on a quartz substrate, with the metal circuit being electroplated metal nickel. Utilizing the band-stop characteristics of SSPPs and the high-frequency high-loss properties of metal nickel, the attenuation and absorption of electromagnetic energy are achieved. The proposed nickel SSPPs waveguide terminator is experimentally validated in the W-band(75~110 GHz). The experimental results indicate that the Return Loss of this waveguide terminator exceeds 15 dB across the entire W-band, with a corresponding electromagnetic absorption rate of over 96.8%.
2025, 23(1):29-34.
DOI: 10.11805/TKYDA2024537
Abstract:
A novel frequency synthesis method for fast frequency hopping in the Ka band is proposed, which achieves frequency spectrum shifting of low-frequency signals through multi-level mixing. A miniaturized, low-power, and simple frequency implementation method is also proposed. This method can achieve fast frequency hopping and incorporates an implementation method of in-loop mixing on the basis of the original design method, which can greatly reduce the N-division ratio of the Phase-Locked Loop(PLL) and improve the phase noise of the output signal. The improved frequency synthesis method compensates for the shortcomings of the original frequency synthesis method and can be extended and applied to multiple types of communication and radar systems. After engineering verification, the new Ka band agile frequency synthesis technology has achieved significant results and can solve practical problems that hinder the engineering application of direct frequency synthesis technology. It is a new Ka band agile frequency synthesis technology that can be promoted and applied.
A novel frequency synthesis method for fast frequency hopping in the Ka band is proposed, which achieves frequency spectrum shifting of low-frequency signals through multi-level mixing. A miniaturized, low-power, and simple frequency implementation method is also proposed. This method can achieve fast frequency hopping and incorporates an implementation method of in-loop mixing on the basis of the original design method, which can greatly reduce the N-division ratio of the Phase-Locked Loop(PLL) and improve the phase noise of the output signal. The improved frequency synthesis method compensates for the shortcomings of the original frequency synthesis method and can be extended and applied to multiple types of communication and radar systems. After engineering verification, the new Ka band agile frequency synthesis technology has achieved significant results and can solve practical problems that hinder the engineering application of direct frequency synthesis technology. It is a new Ka band agile frequency synthesis technology that can be promoted and applied.
2025, 23(1):44-48.
DOI: 10.11805/TKYDA2024395
Abstract:
A high-power frequency doubler at 200 GHz has been designed and implemented based on GaN Schottky diodes. This frequency doubler replaces traditional GaAs Schottky diodes with high-power-capacity Gallium Nitride(GaN) Schottky diodes and combines them with Aluminum Nitride(AlN) substrates, which have high thermal conductivity, significantly enhancing the heat dissipation and output power of the doubler. A suspended microstrip-waveguide transition structure with a wedge-shaped membrane is employed, which realizes mode conversion and codirectional input and output by inserting a wedge-shaped membrane into the standard rectangular waveguide, achieving miniaturization of the frequency doubler. Considering the impact of temperature on diode operation, the traditional diode model is modified, and electro-thermal coupled simulations are performed. Actual test results indicate that under 500 mW continuous-wave input, the doubler outputs more than 20 mW in the frequency range of 190~220 GHz and achieves a maximum output power of 36 mW at 218 GHz, with a conversion efficiency of 7.2%.
A high-power frequency doubler at 200 GHz has been designed and implemented based on GaN Schottky diodes. This frequency doubler replaces traditional GaAs Schottky diodes with high-power-capacity Gallium Nitride(GaN) Schottky diodes and combines them with Aluminum Nitride(AlN) substrates, which have high thermal conductivity, significantly enhancing the heat dissipation and output power of the doubler. A suspended microstrip-waveguide transition structure with a wedge-shaped membrane is employed, which realizes mode conversion and codirectional input and output by inserting a wedge-shaped membrane into the standard rectangular waveguide, achieving miniaturization of the frequency doubler. Considering the impact of temperature on diode operation, the traditional diode model is modified, and electro-thermal coupled simulations are performed. Actual test results indicate that under 500 mW continuous-wave input, the doubler outputs more than 20 mW in the frequency range of 190~220 GHz and achieves a maximum output power of 36 mW at 218 GHz, with a conversion efficiency of 7.2%.
2025, 23(1):56-60.
DOI: 10.11805/TKYDA2024380
Abstract:
Due to the short wavelength of millimeter-wave radar, azimuth sampling ambiguity is more likely to occur under certain Pulse Repetition Frequency(PRF) conditions, and the imaging quality is greatly affected by the estimation of the Doppler center frequency. To address this, a method for estimating the Doppler center frequency by combining inertial navigation information and echo envelope symmetry matching is proposed, which can accurately estimate the Doppler center frequency for millimeter-wave Synthetic Aperture Radar(SAR) imaging, thereby achieving the goal of stable and continuous image generation. Firstly, inertial navigation information is employed to resolve azimuth sampling ambiguity, and then the proposed echo envelope symmetry matching method is adopted to achieve precise estimation of the Doppler center frequency. This method has high estimation accuracy and low algorithm complexity, making it suitable for different frequency band radars and various time-frequency domain imaging algorithms, demonstrating good universality. The effectiveness of the algorithm in this paper is verified through continuous estimation of SAR image sequences and performance comparison of the algorithms.
Due to the short wavelength of millimeter-wave radar, azimuth sampling ambiguity is more likely to occur under certain Pulse Repetition Frequency(PRF) conditions, and the imaging quality is greatly affected by the estimation of the Doppler center frequency. To address this, a method for estimating the Doppler center frequency by combining inertial navigation information and echo envelope symmetry matching is proposed, which can accurately estimate the Doppler center frequency for millimeter-wave Synthetic Aperture Radar(SAR) imaging, thereby achieving the goal of stable and continuous image generation. Firstly, inertial navigation information is employed to resolve azimuth sampling ambiguity, and then the proposed echo envelope symmetry matching method is adopted to achieve precise estimation of the Doppler center frequency. This method has high estimation accuracy and low algorithm complexity, making it suitable for different frequency band radars and various time-frequency domain imaging algorithms, demonstrating good universality. The effectiveness of the algorithm in this paper is verified through continuous estimation of SAR image sequences and performance comparison of the algorithms.
2025, 23(1):66-72.
DOI: 10.11805/TKYDA2024542
Abstract:
To address the challenge that digital phased arrays cannot be calibrated using traditional vector network analyzers, a near-field measurement-based digital phased array calibration system is proposed. By employing a method of providing a local oscillator through a mixer and signal source in addition to the vector network analyzer, the architecture of the digital phased array antenna calibration system for both transmission and reception states has been designed, achieving the same frequency network parameter measurement of the digital phased array using the vector network analyzer. By designing a timing distribution unit, the automated testing of multi-frequency digital phased arrays has been realized, significantly reducing the measurement time. After actual measurement, the reception and transmission amplitude and phase calibration of 20 antenna units are successfully completed, and the phase consistency after calibration can be stably maintained within a range of ±7°.
To address the challenge that digital phased arrays cannot be calibrated using traditional vector network analyzers, a near-field measurement-based digital phased array calibration system is proposed. By employing a method of providing a local oscillator through a mixer and signal source in addition to the vector network analyzer, the architecture of the digital phased array antenna calibration system for both transmission and reception states has been designed, achieving the same frequency network parameter measurement of the digital phased array using the vector network analyzer. By designing a timing distribution unit, the automated testing of multi-frequency digital phased arrays has been realized, significantly reducing the measurement time. After actual measurement, the reception and transmission amplitude and phase calibration of 20 antenna units are successfully completed, and the phase consistency after calibration can be stably maintained within a range of ±7°.
2025, 23(1):1-5.
DOI: 10.11805/TKYDA2024399
Abstract:
A new design and fabrication method for an E-band frequency doubler module is introduced. The module utilizes a quartz probe in the form of a quasi-Yagi antenna to achieve efficient signal transition from the chip to the rectangular waveguide. To suppress the higher-order mode resonance generated in the packaged chip cavity, a pin-shaped electromagnetic bandgap structure is introduced to expand the operating bandwidth. To verify this method, the module is optimized through simulation, processed, and tested. The test results show that with an input power of 13 dBm, it is capable of outputting radio frequency signals with frequencies in the range of 60~80 GHz and power greater than 0 dBm. The test results match well with the on-chip test results of the chip, proving the feasibility of this method.
A new design and fabrication method for an E-band frequency doubler module is introduced. The module utilizes a quartz probe in the form of a quasi-Yagi antenna to achieve efficient signal transition from the chip to the rectangular waveguide. To suppress the higher-order mode resonance generated in the packaged chip cavity, a pin-shaped electromagnetic bandgap structure is introduced to expand the operating bandwidth. To verify this method, the module is optimized through simulation, processed, and tested. The test results show that with an input power of 13 dBm, it is capable of outputting radio frequency signals with frequencies in the range of 60~80 GHz and power greater than 0 dBm. The test results match well with the on-chip test results of the chip, proving the feasibility of this method.
2025, 23(1):24-28.
DOI: 10.11805/TKYDA2024555
Abstract:
With the rapid development of electronic information technology in recent years, millimeter waves have been increasingly applied to communication, imaging, electronic countermeasures, radar, and guidance systems. In response to the limitation that domestic Successive Detector Logarithmic Video Amplifiers(SDLVAs) have difficulty in continuous detection in the millimeter wave band, a detection circuit design scheme based on the down-conversion mode is proposed. By using an internal local oscillator to down-convert the 26~38 GHz RF signal to 3~15 GHz, and then using a domestic SDLVA chip to perform continuous detection logarithmic video amplification on 3~15 GHz, the product design and testing show that this millimeter wave broadband detection can achieve a sensitivity of -57 dBm and a large dynamic detection output of 37 dB in a wide temperature range of -55~+70 ℃. The product features full domestication and miniaturization, giving it a significant advantage in broadband millimeter wave detection.
With the rapid development of electronic information technology in recent years, millimeter waves have been increasingly applied to communication, imaging, electronic countermeasures, radar, and guidance systems. In response to the limitation that domestic Successive Detector Logarithmic Video Amplifiers(SDLVAs) have difficulty in continuous detection in the millimeter wave band, a detection circuit design scheme based on the down-conversion mode is proposed. By using an internal local oscillator to down-convert the 26~38 GHz RF signal to 3~15 GHz, and then using a domestic SDLVA chip to perform continuous detection logarithmic video amplification on 3~15 GHz, the product design and testing show that this millimeter wave broadband detection can achieve a sensitivity of -57 dBm and a large dynamic detection output of 37 dB in a wide temperature range of -55~+70 ℃. The product features full domestication and miniaturization, giving it a significant advantage in broadband millimeter wave detection.
2025, 23(1):40-43.
DOI: 10.11805/TKYDA2024398
Abstract:
InP/InGaAs Schottky Barrier Diodes(SBDs) detectors, due to their high electron mobility and low barrier material characteristics, have a very high voltage response sensitivity and are widely used in highly sensitive terahertz wave detection technology. To further reduce device parasitic effects and enhance its high-frequency performance, a novel structure of substrate-free single-mesa T-junction Schottky device is proposed, with a cutoff frequency of 9.5 THz. Based on the novel structure of InP/InGaAs Schottky device technology, terahertz detector modules for multiple frequency bands such as 220~330 GHz, 30~500 GHz, 400~600 GHz, and 500~750 GHz have been developed. Compared with the detectors of the same frequency band from VDI Company in the United States, the detection sensitivity and other indicators are similar, indicating that the device has a promising application prospect in terahertz security imaging.
InP/InGaAs Schottky Barrier Diodes(SBDs) detectors, due to their high electron mobility and low barrier material characteristics, have a very high voltage response sensitivity and are widely used in highly sensitive terahertz wave detection technology. To further reduce device parasitic effects and enhance its high-frequency performance, a novel structure of substrate-free single-mesa T-junction Schottky device is proposed, with a cutoff frequency of 9.5 THz. Based on the novel structure of InP/InGaAs Schottky device technology, terahertz detector modules for multiple frequency bands such as 220~330 GHz, 30~500 GHz, 400~600 GHz, and 500~750 GHz have been developed. Compared with the detectors of the same frequency band from VDI Company in the United States, the detection sensitivity and other indicators are similar, indicating that the device has a promising application prospect in terahertz security imaging.
2025, 23(1):49-55.
DOI: 10.11805/TKYDA2024394
Abstract:
Mountainous environments typically feature diverse terrains. To address the issue of complex signal propagation paths in wireless communication due to terrain obstructions in mountainous areas, a modeling method for terahertz wireless communication under different mountain slopes is proposed. Terrain data is obtained through Digital Elevation Models(DEM), and the ray tracing method is combined with the introduction of a slope factor to analyze the propagation characteristics of terahertz signals in mountainous areas. Simulation experiments are conducted on the received power of the receiver to establish a quantitative relationship between terrain slope and received power. Simulation results indicate that there are significant differences in signal coverage and delay characteristics across regions with different slopes:flatter areas in the mountains generally have more stable signal coverage with a more concentrated power distribution(-172.5~-117.5 dBm); whereas in areas with steep slopes, signal coverage is poor, power distribution is more dispersed, but delay spread distribution is more concentrated (0~3 ns).
Mountainous environments typically feature diverse terrains. To address the issue of complex signal propagation paths in wireless communication due to terrain obstructions in mountainous areas, a modeling method for terahertz wireless communication under different mountain slopes is proposed. Terrain data is obtained through Digital Elevation Models(DEM), and the ray tracing method is combined with the introduction of a slope factor to analyze the propagation characteristics of terahertz signals in mountainous areas. Simulation experiments are conducted on the received power of the receiver to establish a quantitative relationship between terrain slope and received power. Simulation results indicate that there are significant differences in signal coverage and delay characteristics across regions with different slopes:flatter areas in the mountains generally have more stable signal coverage with a more concentrated power distribution(-172.5~-117.5 dBm); whereas in areas with steep slopes, signal coverage is poor, power distribution is more dispersed, but delay spread distribution is more concentrated (0~3 ns).
2025, 23(1):61-65.
DOI: 10.11805/TKYDA2024404
Abstract:
A microstrip antenna size optimization method based on K-Nearest Neighbors(KNN) and Artificial Neural Network(ANN) algorithms is proposed to solve the problem of high optimization complexity of traditional antennas. By analyzing the surface current distribution of the antenna, high-sensitivity parameters are set as variables, while low-sensitivity parameters are set as constants. The KNN algorithm and ANN algorithm are then utilized to optimize the size parameters of the antenna, ultimately enhancing broadband performance. To validate the effectiveness of the optimization algorithms, two antennas were fabricated and tested. The results indicate that compared to traditional antenna design methods, the KNN and ANN algorithms increase the impedance bandwidth by 20.8% and 18.4%, respectively. Although the ANN algorithm requires longer training time, it demonstrates significant improvements in impedance matching across multiple frequency bands.
A microstrip antenna size optimization method based on K-Nearest Neighbors(KNN) and Artificial Neural Network(ANN) algorithms is proposed to solve the problem of high optimization complexity of traditional antennas. By analyzing the surface current distribution of the antenna, high-sensitivity parameters are set as variables, while low-sensitivity parameters are set as constants. The KNN algorithm and ANN algorithm are then utilized to optimize the size parameters of the antenna, ultimately enhancing broadband performance. To validate the effectiveness of the optimization algorithms, two antennas were fabricated and tested. The results indicate that compared to traditional antenna design methods, the KNN and ANN algorithms increase the impedance bandwidth by 20.8% and 18.4%, respectively. Although the ANN algorithm requires longer training time, it demonstrates significant improvements in impedance matching across multiple frequency bands.
2025, 23(1):35-39.
DOI: 10.11805/TKYDA2024522
Abstract:
A broadband Transimpedance Amplifier(TIA) chip architecture and circuit design suitable for highspeed optical receiver systems are proposed. The TIA chip, as the backend circuit of the photoelectric detector, can amplify the high speed photo-current of the detector with a low input referred noise and meet the requirements of system-level speed and sensitivity. The high-speed TIA design architecture consists of three parts: the TIA core circuit, the single-ended to differential conversion circuit, and the limiting amplifier circuit. In the design of the limiting amplifier, the Miller effect is utilized to introduce tunable capacitors to balance the output voltage amplitude, bandwidth, and circuit stability of the high-frequency circuit, achieving broadband signal reception, limiting amplification, and external driving functions, thereby enhancing the quality of high-speed transmission signals. By conducting small-signal amplitude-frequency characteristic analysis, noise simulation, and large-signal time-domain analysis of the chip under different process corners, the bandwidth, noise, sensitivity and transmission characteristics of the TIA chip are further verified.
A broadband Transimpedance Amplifier(TIA) chip architecture and circuit design suitable for highspeed optical receiver systems are proposed. The TIA chip, as the backend circuit of the photoelectric detector, can amplify the high speed photo-current of the detector with a low input referred noise and meet the requirements of system-level speed and sensitivity. The high-speed TIA design architecture consists of three parts: the TIA core circuit, the single-ended to differential conversion circuit, and the limiting amplifier circuit. In the design of the limiting amplifier, the Miller effect is utilized to introduce tunable capacitors to balance the output voltage amplitude, bandwidth, and circuit stability of the high-frequency circuit, achieving broadband signal reception, limiting amplification, and external driving functions, thereby enhancing the quality of high-speed transmission signals. By conducting small-signal amplitude-frequency characteristic analysis, noise simulation, and large-signal time-domain analysis of the chip under different process corners, the bandwidth, noise, sensitivity and transmission characteristics of the TIA chip are further verified.
