A low phase noise X-band MMIC GaAs MESFET VCO

Abstract

We present a fully monolithic X-band VCO MMIC implemented in a commercial GaAs MESFET process. Measurement results demonstrate a single sideband phase noise of 91 dBc/Hz at a 100 KHz offset. This VCO achieves a maximum output power of 11.5 dBm with 12 dB of output power control and a 550 MHz of frequency tuning range. Second harmonic suppression of 20 dB or more is measured across the entire power and frequency range. These results are comparable to, or better than, the best reported results of VCO's implemented in high electron mobility transistor (HEMT) and heterojunction bipolar transistor (HBT) processes.

A compact LTCC-based Ku-band transmitter module

“…The load impedance is carefully designed to increase the -factor of the resonator. Although a much wider tuning bandwidth can be obtained by placing the varactor on the gate path, the varactor is incorporated in the resonator on the source path to reduce its noise contribution to the VCO [7]. To eliminate undesirable low frequency oscillations, a LC network is also incorporated as a high pass filter on the output path.…”

A Two-Dimensional (2D) Analytical Model for the Potential Distribution and Threshold Voltage of Short-Channel Ion-Implanted GaAs MESFETs under Dark and Illuminated Conditions

“…GaAs Metal-Semiconductor Field Effect Transistors (GaAs MESFETs) have drawn considerable attention for the designing of high-speed digital/analog integrated circuits and microwave monolithic ICs [1][2][3][4][5][6][7][8][9]. A number of studies have illustrated that both the dc and microwave characteristics of a GaAs MESFET can be modified by coupling a fraction of the optical power radiated by an external source into the channel of the device [10][11][12][13][14][15][16][17].…”