A Ku-band MMIC PLL frequency synthesizer

A Ku-band PLL (phase-locked-loop) frequency synthesizer has been developed in a very compact configuration, incorporating two novel monolithic GaAs chips: an MMIC (monolithic microwave integrated circuit) and an LSI circuit. The MMIC includes a Ku-band VCO (voltage-controlled oscillator), a dual-output buffer amplifier, a balun, and a dynamic/static prescaler. A very small chip size has been realized by a uniplanar configuration. The LSI chip includes a dual-modulus prescaler, programmable counters, and a phase/frequency comparator. The proposed synthesizer exhibits a tuning range broader than 1 GHz and a phase noise of about -70 dBc/Hz at 1 kHz offset from the carrier. Since the proposed synthesizer is both compact and rugged, it should contribute to the development of very small digital-tuning microwave transmitters and receivers that could be applied in radio communication equipment.<>