A Low Phase Noise Microwave Oscillator with a Miniaturized LTCC Resonator for SIP Design

This paper presents an oscillator employing miniature, high-Q, low temperature cofired ceramic (LTCC) resonator in conjunction with a novel implementation technique for achieving low phase noise. The reduced-size LTCC resonator is realized with a dielectric material having epsiv_r = 68, the first ever reported. As well, the oscillator circuitry design exploits the seldom used device-line technique for obtaining the lowest possible phase noise with any chosen component. A free-running, 6 GHz oscillator using GaAs p-HEMT active device is built in a planar hybrid format suitable for system-in-package (SIP) designs. The measured phase noise is -125 dBc/Hz at 1 MHz offset, with over 8 dBm of output power, which compares favorably with the best C-band oscillators. The technique herein demonstrates the feasibility of miniaturized, low-cost, SIP products