Simulation Design And Research Of Ka Band Sub Harmonic Mixer

This paper, using harmonic mixing technology to realize the broadband conversion, is mainly responsible for the Ka-band harmonic mixing design and related development, making the harmonic mixer with the operating frequency 20.48 GHz and the local oscillation 8.24 GHz. Signal inputs and outputs are used microstrip circuit design. Signal input terminal is provided with low-pass filter, and the output is provided with bandpass filter to suppress band mixing products. Each filter circuit design are carried out before the simulation, in order to better control the mixer loss. Also each of the impedance matching of thenetwork port uses ADS simulation analysis, so that in the effective operation of the bandwidth to achieve that the conversion loss is within 15 dB, in-band amplitude frequency is less than 0.6 dB, the isolation between the ports is 20 dB or more, and to achieve the intended technical indicators. According to the index requirements and the existing conditions, this paper uses anti-parallel diodes(MA4E2039) to complete the second-harmonic mixing function.The paper gives a profound introduction to the harmonic mixer, analyses and elaborates the harmonic mixing function and technical requirements. And the paper also discusses the working principle of harmonic mixer in graphic manner, and ultimately determines the system design scheme of harmonic mixer.Furthermore, the paper also studies the diode parameter, filter circuit, frequency doubling circuit, interface design, impedance matching and etc. and puts physical samples into operation and tests related technical indicators, analyzing the test results finally.Due to the use of microwave integrated circuit technology, this design of the Ka-band harmonic mixer has the advantages of low manufacturing cost, reliable, batch production and wide application range.The mixer is the key component to receive system, and the use of the mixer can improve the rf performance of the whole system. So the design has a greater guidance value both in military or civilian applications, and also provides a reference value for the future design and research.