RECIPROCAL AND NONRECIPROCAL MICROSTRIP PERIODIC NETWORKS
Final rept. 15 Sep 1966-15 Jun 1967
MASSACHUSETTS INST OF TECH LEXINGTON LINCOLN LAB
Pagination or Media Count:
The report presents results of an investigation of a microstrip filter which was designed for the study of nonreciprocal phase in S-band about 3 GHz. Data are presented showing scattering, absorption, and nonreciprocity. The device is a low-pass comb filter. When matched to less than 1.11 VSWR over a 13 band, its insertion loss is 0.8 - 1.2 db. Nonreciprocal differential phase is frequency-sensitive, reaching 30 degrees near the cutoff frequency of 3.5 GHz. An analysis is presented of the theory of periodic networks with sufficient generality to include the nonreciprocal and nonconservative cases. Comparison with the performance of a reciprocal filter shows good agreement. The agreement with nonreciprocal effects is qualitatively correct, although a full treatment of nonreciprocity must await a detailed field theory of propagation on microstrip with a magnetic substrate. The investigation shows that substantial amounts of nonreciprocal phase can be produced by means of a simple, compact, efficient microstrip structure with low loss and good match over an ample band, suitable for control in the latching remanent mode of operation.
- Electrical and Electronic Equipment