1.9 GHz Compact Low Loss Dielectric Duplexer Designed by Dual Mode Waveguide Transmission Line Method
A new small sized and low loss 1.9 GHz band dielectric duplexer has been developed. 1.9 GHz TM110 dual mode monoblock dielectric resonators, which designed to have much smaller volume (27 cc) and high unloaded Q(5000), have been constructed by using new precise molding techniques. And to insure that we are able to simulate and design optimized electrical performance of the duplexer accurately, we have proposed a dielectric dual mode waveguide transmission line design, method. The duplexer thus designed and manufactured has excellent performanc. The volume is 200 cc, insertion loss is 0.45 dB, and attenuation is 85 dB.
Low profile filter using open disk dual mode dielectric resonators for microcellular base station
This paper present a low profile bandpass filter using open disk dual mode dielectric resonators for microcellular base stations. The resonator consists of two dielectric disks in a cylindrical cavity, and the torus electrode increases the unloaded Q of the resonator. An equivalent circuit consisting of ring shaped transmission line with electrical length of 2¿ represents the dual mode resonator. A multi-pole bandpass filter can be designed by the Chebysheff type deign method. A 6-pole bandpass filter with the center frequency of 947.5 MHz and insertion loss of 0.7dB is fabricated. Measured response of the filter agrees with the simulated one. The dimensions of the filter are 158×54×23.5 mm.
Coherent pulsed injection seeding of two gain-switched semiconductor lasers
High-power, narrow-spectrum, short pulses at a wavelength near 830 nm are needed for optical logic applications. The authors report the generation of two coherent trains of pulses by pulsed injection seeding of two gain-switched semiconductor lasers with one mode-locked master oscillator. The available power was doubled and both lasers emit in nearly identical spectral lines. Short pulses (30-50 ps) are generated at a repetition rate of 1.9 GHz. The spectrum is reduced to a single mode cluster and shows a 1.7 AA wide chirp suitable for pulse compression. The peak power is 0.1 W for each pulse train. The capability of this technique for coherent power combining is demonstrated.<<ETX>>