| Millimeter-wave(MMW) is an important cross-subject of microwave and optics. Mixers are the key components of millimeter-wave systems. Having the property of good image rejection in broadband and low intermediate frequency(IF) cases, the image rejection mixers(IRM) have been widely used in various MMW receivers. In MMW band ,generating LO signal with high quality is difficult and costly. Harmonic mixer is a good solution to this problem now. In this circuit ,we need just half or quarter of MMW LO frequency.At first, the basic operating principle of image rejection mixer and harmonic mixer are introduced in this thesis. Then the design and implementation of 3 millimeter wave microstrip hybrid integrated second and fourth harmonic mixers are presented. On the base of fourth harmonic mixer, image rejection harmonic mixer of 3 millimeter wave is fabricated . The IRM consists of two unit fourth harmonic mixers, RF cophase power divider, LO quadrature coupler and IF quadrature coupler.The mixers are designed,simulated and optimized using circuit simulation software ADS(advanced design system) and electromagnetic simulation software Ansoft HFSS. The analysis of harmonic balance is used in the whole circuit simulation .When RF frequency is 93-97GHz and IF is 70MHz, the conversion loss of the second and fourth harmonic mixers are 11.7-14.8dB and 14.2-16dB which are shown in the test. The best conversion loss and image rejection of IRHM are 10.2dB and 26dB.Improvement is introduced in the end. As a key component of receive system, mixer plays an important role and it improves the performance of all system directly.This thesis is meaningful in no matter military field or commercial field in practice. Also,it has shown the effectiveness of design method in this thesis by comparing the designed and measured results. |
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