V-band high-power low phase-noise monolithic oscillators and investigation of low phase-noise performance high drain bias

Abstract

This paper reports on the excellent performance of V -band monolithic high electron-mobility transistor (HEMT) oscillators, and discusses oscillation characteristics on drain bias. With regard to output characteristics, double-hetero (DH) HEMT (especially with a high-density Si-planar doped layer) are superior to single-hetero (SH) HEMT's. A monolithic microwave integrated circuit (MMIC) oscillator has been developed with a planar doped DH HEMT and has achieved the peak output power of 11.1 dBm at a 55.9-GHz oscillation frequency. Phase noise of 085 dBc/Hz at 100-kHz offset and 0103 dBc/Hz at 1-MHz offset have been achieved at a drain voltage of 5.5 V and a gate voltage of 0 V. These characteristics have been achieved without any buffer amplifiers or dielectric resonators. This study has revealed that the phase noise decreases as drain voltage increases. This phenomenon is caused by lower pushing figure and lower noise level at a low-frequency range obtained under a high drain voltage. It is because the depletion layer in the channel is extendedto the drain electrode with increase of drain voltage, resulting in the small fluctuation of the gate-to-source capacitance. We also investigate low-frequency noise spectra of AlGaAs/InGaAs/GaAs DH HEMT's with different bias conditions. The low-frequency noise decreases for more than 3 V of the drain voltage. A unique mechanism is proposed to explain this phase noise reduction at high drain voltage.

A low phase noise X-band MMIC GaAs MESFET VCO

“…As the drain voltage increases, the angle approaches 90 where the is at a maximum. Increasing the drain voltage also reduces the phase noise by extending the depletion region in the channel to the drain side and consequently reducing the sensitivity of the oscillator to the gate-source voltage [10]. The noise parameters of the device are measured to determine the optimum matching point for a resonator.…”

High power 60 GHz push push oscillator using InALAs/InGaAs metamorphic HEMT technology

“…Previously reported push-push oscillators were demonstrated using InP HBT, GaAs PHEMT, and SiGe HBTs [5][6][7][8], but the push-push oscillator implemented by using MHEMT was not demonstrated for high power applications at frequencies around 60 GHz. In this paper, we have investigated the potential of pushpush oscillator implemented using MHEMT technology.…”

“…At the present time many existed design techniques could be applied for low-pass filter designs: open-stub [1,2], stepped-impedance [3,4], inter-digital capacitors [5,6], and coupled-line [7,8].…”

104 and 134 GHz InGaP/InGaAs HBT oscillators

“…High-frequency oscillators are key components in achieving future millimeter-wave applications such as measuring instruments, radar systems and wireless communication systems. Several oscillators operating at millimeter-wave frequencies using high electron mobility transistor (HEMT) technology have been reported [ 11- [4]. However, their phase noise performance is limited by the I/f noise of the HEMTs.…”