Key Components Of K-band Broadband Receiver Front-end

Owing to emergency of frequency spectrum resource crisis, research aboutelectrical system in the field of communication, radar-guidance has been widelydeveloped in the millimetre wave frequency band; on the other hand, the rapid growthof technology and the competition armament demand higher performance receiver.Advanced receiver has some better characteristic, such as high resolution capacity, highintegration, high dependability and better anti-jamming ability. This dissertationanalyses the characteristic of wideband receiver and key technology, and present someresearch in progress, which goal is to provide feasible prototype and experiment data fornew-style wideband receiver research in future.In different type modern receiver with various system and working band,theschemes of receiver are diverse. The design of millimetre wave receiver front-endsystem is carefully analyzed. According to the design goals of system, The indicators’assigning of millimetre-wave receiver front-end subsystem is described. Then thedissertation focuses on the analysis of the working principle and engineering designmethods of filter and solid-state circuitry including low-noise amplifier and mixer, etc.Combining with the specific requirements of this design, it also gives the design processof the independent device.The thesis completes the work of studying the K-band receiver front-endsubsystem, using the super heterodyne architecture, it can receiver the RF signal atfrequency of20.3-21.7GHz,22.3-23.7GHz,24.3-25.7GHz. First, the RF signal passesthrough the low noise amplifier, because the subsystem requires a smaller noise index,so the noise figure of the low noise amplifier must be low enough, then the signal passesthe filter to filter out spurious signal and image frequency signal, the signal is downconverted with the local oscillator signal through the mixer, it can generate the IF signalof1.3to2.7GHz.The dissertation first introduces the receiver theory, including common receiverstructure analysis,analysis of technical indicators; developed the K-band receiverfront-end design based on theoretical analysis and design requirements; indicators simulation of the system and validation software. Then it introduces the design of everydevice,the low noise amplifier using two cascaded structure ensures noise figure issmall enough, and increases the gain;Then the dissertation focuses on the analysis ofthe working principle and engineering design methods of filter and solid-state circuitryincluding low-noise amplifier and mixer, etc. we made a front-end broadband low-noiseamplifier, IF amplifier, and other key devices, and select the middle of the object as atechnology demonstrator. The receiver front-end subsystem has been tested. The testingresults: noise figure is less than4dB, gain is better than20dB, image rejection is greaterthan40dB.Composition and implementation of receiver for wide-band are introduced in thispaper,at the same time, research result and date are provided together.