Research&Application Of High-performance Millimeter-Wave Frequency Multiplier

Millimeter-wave solid-state frequency source is one of the main means to obtain millimeter-wave signal source,with the advantages of wide bandwidth,small size,light weight,low power consumption,high reliability and so on.Frequency multiplier is the core component of the millimeter-wave solid state frequency source.A stable output signal can be obtained with it by multipling the low frequency signal to the high frequency band.In this paper,the theoretical basis and realization method of the frequency multiplier are studied.For the sake of developing a K-band and W-band solid multiplier of corresponding frequency band with low cost and meeting the application requirements of the project,through the establishment of accurate three-dimensional equivalent model of Schottky diode,a suitable circuit design scheme is adopted to improve the design reliability and obtain the frequency multiplier as much as possible to meet the requirements of the index.In addition,the frequency multiplying chain combining power amplifier and filters is successfully applied in millimeter-wave frequency multiplier source system.The main contents of this thesis are as follows:1.Based on the Schottky anti-paralleled diode pair(APDP)DMK2308,a K-band tripler with good flatness of output power is developed by using a simple and reliable series-balanced frequency doubling structure.The output end of the tripler integrates the bandpass filter of the specified frequency band,carries on the integrated simulation optimization to remove the coupling between the circuits,realizes the good frequency selective characteristic and effectively filters out the system out-of-band clutter.Based on the full-scale three-dimensional equivalent circuit model of diode pair,the input and output matching and filter circuits of the frequency multiplier are optimized by using the field-circuit simulation method combining HFSS and ADS.Finally experimental samples are processed.The test results show that,in the output frequency range of 21.6-24.9GHz,with the input driving power of 12dBm,the typical frequency multiplication loss is 16dB and the output power flatness is between 1.6dBTthe test and simulation results have good agreement and the out-of-band inhibition is obvious.In order to tie in with the power ratio of the cascaded modules before and after,two stages and one stage of amplification are respectively added to the input end and the output end to achieve the frequency doubling amplification module.When the input power of-12dBm is provided,the output power is typically 18dBm and the frequency conversion gain reaches 30dB and the passband output power fluctuations are only 2.2dB.2.In view of the MA4E1310 diode from Macom Corp.,a balanced doubler with frequency range 14-23.2GHz is developed based on the balanced Erickson frequency multiplication structure and hybrid integration technology.Through the well-designed microstrip waveguide transition structure,the fundamental wave signal is fed by the WR90 waveguide.Besides,the second harmonic signal is used to output with the maximum power by the field-circuit simulation method and selecting the suitable input-output matching structure.Sensitivity analysis is conducted on the important parameters with high processing and installation accuracy and methods to effectively increase the power capacity are also studied.After the experimental study,when the input power of 18dBm,4.5dBm of typical output power of frequency doubler is produced over 14-23.2GHz.The typical value of frequency multiplication loss id 13dB and passband flatness characteristics are better.Similar to the K-band tripler,in order to facilitate the practical application,a two-stage amplifier is added in front of the microstrip waveguide transitional structure to form an active doubler module.The test results show that when driven with-3dBm of input power,the output power is typically 3 dBm and the gain is 6dB,meeting the system application requirements.3.Adhere to the principle of economic reliability,based on the successful experience of the K-band doubler about the MA4E1310 diode,the anti-parallel structure is also adopted.According to the sensitivity parameters analyzed in Chapter 4,the impedance characteristics of the diode mounting area are studied separately.Of the input and output matching and filtering circuit,focusing on two transitional structure like probe and the "embedded" fin line,to ensure that the process can be achieved at the same time,the frequency tripler has been processed in-kind and experimentally over the W band between 78GHz and 105GHz.The test results show that the typical frequency multiplication loss of the fin-line and probe type frequency multipliers is 17.5dB and 19dB respectively,and the output power flatness is between 1.5dB when the driving power is about 20dBm in the output frequency range of 78-105GHz.The test results and simulation results are basically consistent wiyh high design reliability.4.Based on the successful development of the K-band and W-band frequency multipliers,it is cascaded with the existing power amplifier and filter modules in the laboratory to form the frequency-doubling link in the millimeter-wave frequency multiplier source system.Through overall coordination of the input and output power and spectral characteristics among the sub-modules,the cascaded modules are successfully cascaded according to the indicator requirements to achieve stable output of the W-band signal.The experimental results show that the typical output power of the W-band tripler is ldBm,the fluctuation range is within 1dB and the flatness characteristic is good when the signal source provides driving power of-3 dBm in the output band covering 90-102GHz.