A fast-switching low-loss 12-GHz microstrip 4-PSK path length modulator
Abstract
A 4-PSK microstrip modulator operating at data rates of up to 800 Mbits/sec at 12 GHz is described. The circuit is made of two cells in series. Each cell consists of a 3-dB branch-line hybrid coupler and two BTL p-i-n diodes. One cell provides 0 or 90 deg phase shifts, and the other 0 or 180 deg phase shifts, so that four carrier phase values are obtained by appropriately exciting the two cells. The switching time of each cell is 200 psec. Simultaneous switching of both cells increases the switching time to a maximum value of 400 psec. The phase waveforms are nearly rectangular at the above-mentioned data rates. RF insertion loss is 1 dB + or - 0.1 dB for the four phase values over the 11.7-12.2 GHz frequency band.
- Publication:
-
IEEE Transactions on Communications
- Pub Date:
- October 1980
- Bibcode:
- 1980ITCom..28.1824G
- Keywords:
-
- Insertion Loss;
- Microstrip Transmission Lines;
- Microwave Switching;
- Modulators;
- Phase Shift Keying;
- Time Lag;
- Channel Capacity;
- Data Transmission;
- Hybrid Circuits;
- Junction Diodes;
- Microwave Coupling;
- P-I-N Junctions;
- Phase Modulation;
- Superhigh Frequencies;
- Waveforms;
- Electronics and Electrical Engineering