A 12 GHz oscillator based on a GaAs HEMT integrated to a HTS resonator

Abstract

A hybrid oscillator operating at 12 GHz and 77 K was designed and characterised. The design incorporated on a single substrate a passive superconductive circuit and a 111-V active device. YBaCuO films (300nm), grown on MgO, had a surface resistance at 77 K of 0.3 m a scaled to 12 GHz. The DC and RF characteristics of the pseudomorphic HEMT showed minor differences before and after hybridation. The characterisation of a preliminary prototype oscillator including a superconducting resonator patterned on a MgO substrate, a gold matching network fabricated on A1203 and a transistor wire bonded gave a phase noise as low as-75 dBc/Hz at 10 KHz.

A Low Phase Noise All Cryogenic Microwave Oscillator Based on a Superconductor Resonator

“…Moreover, the resonator frequency is also slightly shifted towards lower frequencies because of the change is the superconductor skin effect. In order to take into account this behavior in the simulations, an RLC circuit model with two nonlinear elements has been developed [8]. The model is depicted in Figure 9 and the nonlinear elements are the intrinsic resistor R and inductor L which are dependent on the instantaneous current I in the resonator.…”

“…It degrades with f 2 when the frequency increases and this explains why HTS technology performs better in the low microwave range. Contrarily to the first projects on hybrid superconductor oscillators in the 1990s [7,8], we have chosen to work at 1 GHz, which allows to reach unloaded quality factors higher than 200 000 for this type of resonator at 77 K [9,10]. Besides, 1 GHz is a popular frequency to generate frequency combs used to stabilize synthesizers in the whole microwave range.…”

An X-band HEMT microwave oscillator stabilized with a superconducting resonator

“…Different approaches to circuit implementation have already been discussed [1][2][3][4][5][6]. A conventional parallel feedback design on an RT/Duroid substrate (ε r = 10.4) is chosen for the oscillator topology, due to the simplicity of incorporating a resonator implemented onto a 5 mm×5 mm LaAlO 3 substrate.…”

Microwave Measurements on YBaCuO Thin Films and Realisation of Microwave Superconducting Devices

“…We have described previously [6] the principle and preliminary results on a 12GHz oscillator based on a GaAs transistor assembled with HTS passive components. The technological realisation was essentially a classical hybridation of the transistor with gold bonding wires to the circuits (HTS resonator and metallic matching network).…”

“…The next step we present here is the realisation and characterisation of a quasi integrated oscillator on a LaA103 single substrate, 500pm thick and of lcm2 area. The integration of the HEMT transistor, key part of the work, is realised by Flip-Chip or Epitaxial Lift Off @LO) after deposition and patterning of the HTS film (300nm thick) at IMEC [6]. The chosen oscillator configuration is in reflection mode with an YBaCuO ring resonator inserted in the gate of the transistor (see the design figure 9).…”