Design Of W-band Planar Passive Circuits

W-band T/R module is an important part of seekers. In order to realize the planar andcompact W-band T/R module, some planar passive circuits, such as filters and powerdivider are studied in this thesis. Coupling resonating filters are realized by utilizingsubstrate integrated waveguide structure, and a Wilkinson power divider is completed withthin film circuit technology.Substrate integrated waveguide is a novel kind of transmission line, which have bothadvantages of rectangle waveguide and microstrip line, and it has been attracted highlyintention in application of high performance passive devices and antennas. This article usesthe symmetry of electric-wall and magnetic-wall to analyze and uses simulation software toextract the coupling coefficients of the filters. In this article, a negative coupling structure isused to bring in transmission zeros on both sides of the band, getting sharper cut-offfrequencies, and better frequency selective characteristic.By using thin film circuits technology, thin film resistor can be integrated in the planarcircuits, and its value can keep accurate even in microwave band. Wilkinson power divideris very easy to be fabricated, and it has better isolation characteristic than common Tjunction. This article uses odd-even mode to analyze and design, and thin film circuitstechnology is used to realize the W-band microstrip Wilkinson power divider.Finally, this article gives a brief introduction of how these planar filters and powerdividers are applied in W-band planar integrated transmit/receive module, which provesthat these planar passive circuit units are useful and meaningful.