Yingjie Jay Guo

A high-temperature superconducting monolithic microwave integrated Josephson down-converter with high conversion efficiency

A compact high-Tc superconducting monolithic microwave integrated circuit Josephson down-converter is presented. The circuit consists of a single Josephson junction mixer, a bandpass filter, a lowpass filter, and a resonator for local oscillator fabricated on a single 10u2009mmu2009×u200920u2009mm chip of YBa2Cu3O7−x film on MgO substrate. The down-converter demonstrates superior performance in terms of conversion efficiency, dynamic range, linearity, and low local oscillator power with stable operation from 20 to 77u2009K. A maximum conversion gain of −4.7 dB was measured at 20u2009K and −12.8u2009dB at 70u2009K.

Self-pumped HTS Josephson heterodyne tunable mixer

Experimental evaluation of a high-temperature superconducting Josephson heterodyne mixer based on a ‘resistive-SQUID’ configuration is reported. The device consists of two YBa2Cu3O7 x step-edge Josephson junctions connected via a small resistor in an otherwise superconducting loop. It has been previously shown to generate a heterodyne oscillation, which is frequency-tunable by a control current through the resistor. Under certain conditions, this device can operate as a frequency-tunable heterodyne mixer (down-converter) in the presence of an RF signal. In this paper, we describe the operation of the autonomous Josephson mixer‐local oscillator device and present the experimental results on the mixer performances in terms of the junction current‐voltage characteristics, the frequency tunability, linearity, and dynamic range as well as their temperature dependence for signal frequencies from 1 to 5 GHz. (Some figures may appear in colour only in the online journal)

Monolithic high-temperature superconducting heterodyne Josephson frequency down-converter

A monolithic microwave integrated circuit (MMIC) frequency down-converter based on a compact high-Tc superconducting (HTS) device is demonstrated. The on-chip integrated HTS down-converter consists of a 7–9u2009GHz bandpass filter for RF input, a lowpass filter for intermediate frequency output, and a self-pumped Josephson heterodyne mixer. All the above passive and active components are fabricated on a single 10u2009mmu2009×u200920u2009mm chip of YBa2Cu3O7−x film on MgO substrate. Characterization of this MMIC HTS down-converter in terms of frequency response, conversion gain, frequency-tuneability, bias dependence, dynamic range, linearity, and intrinsic noise are presented in this paper.

Design and integration of HTS filters with a Josephson device

A high-temperature superconducting (HTS) Josephson frequency down-converting module is demonstrated. An HTS monolithic frequency down-converting circuit and a biasing circuit board for the Josephson device are packaged into the module. The monolithic circuit consists of HTS filters and a Josephson oscillator-mixer device, integrated on a single 10xa0mmxa0×xa020xa0mm chip of Y Ba2Cu3O7−x (YBCO) film on MgO substrate. A compact, low-loss HTS step-impedance low-pass filter was designed for the intermediate frequency (IF) output port. The modeling, simulation and measurement results of the HTS low-pass filter are presented in this paper. The frequency response and dynamic range of the on-chip integrated HTS down-converting module are also described.

A self-pumped high-temperature superconducting Josephson mixer: Modelling and measurement

We have recently developed a high-temperature superconducting (HTS) Josephson self-pumped mixer with an on-chip heterodyne local oscillator. The device is based on HTS step-edge junction technology and a “resistive-superconducting quantum interference device” (RSQUID) configuration. The heterodyne local oscillator and mixer output are frequency-tunable from below 10 MHz to 5u2009GHz by a control current. The performance of the autonomous Josephson mixer–local oscillator has been experimentally evaluated in terms of the current-voltage characteristics, intermediate frequency (IF)-tunable bandwidth, operation range, linearity, bias current, and temperature dependence of the IF output (or mixer conversion efficiency). We find the results are in good overall agreement with numerical simulation.

30 GHz HTS Receiver Front-End Based on Monolithic Josephson Mixer

A compact, high-gain, and low-noise Ka band HTS Josephson junction-based receiver front-end module for wireless communication is presented in this paper. The front-end module consists of biasing circuits, a semiconductor low-noise amplifier, and a monolithic HTS circuit consisting of an Josephson mixer, bandpass and lowpass filters. The semiconductor LNA in the first stage is applied to achieve a low noise figure of the whole front-end module. Integration of the Josephson mixer with a number of HTS passive components on a single chip improves the coupling efficiency and reduces the connection losses between the components. The total dimension of the packaged front-end module is below 25 mm × 20 mm × 15 mm, which is very compact. Measurement result shows that the front-end module has an overall conversion gain around 40 dB, and a low noise figure close to 0 dB with an LO driving power around -38 dBm at 40 K.

A 7–8.5 GHz High Performance MMIC HTS Josephson Mixer

A low-loss, low power consumption monolithic high-temperature superconducting (HTS) Josephson junction mixer at 7-8.5 GHz is presented. The mixer consists of a HTS YBa2Cu3O7-x (YBCO) bandpass filter for RF input, a lowpass filter for IF output and a LO resonator integrated with a single Josephson junction. All the passive and active devices are fabricated on a 20 mm×10 mm MgO substrate. Measurement result shows a conversion gain of -7 dB at 40 K, and -4.7 dB at 20 K. The IF output versus the RF input exhibits a wide linear range of conversion gains. The mixer has an extremely low LO power requirement at -32 dBm and a 50 nW power consumption.

Harmonic Mixing Using a HTS Step-Edge Josephson Junction at 0.6 THz Frequency

A high-temperature superconducting (HTS) terahertz (THz) heterodyne mixer based on a thin-film antenna-coupled YBa2Cu3O7-x step-edge Josephson junction is presented. The frequency down-conversion from 0.6 THz to an intermediate frequency (IF) of 2 GHz was achieved using high-order harmonic mixing of a local oscillator (LO), thus removing the need to use a second THz source as the LO pumping source. The DC and RF characteristics of the harmonic mixer as well as the relationship of the IF output power versus the harmonic number were experimentally studied and compared with simulated results. Most of our measurements were made at 40 K, but we also observed stable harmonic mixing at 77 K which we believe has not been reported previously in HTS junction mixers.

60 GHz to E-Band Switchable Bandpass Filter

A novel reconfigurable millimeter-wave bandpass filter (BPF) capable of operating between 60 GHz and the E-band, with a good channel isolation, is presented. This fully integrated filter is designed with all reconfigurable elements embedded for compactness. A new method that increases fractional bandwidths is introduced. It uses inductively coupled inverters but does not require tuning. New circuit models are provided for these inverters, reconfigurable resonators, and the reconfigurable bandstop stubs. The compact BPF achieved a footprint of only 4.75 mm × 3.75 mm. Measurements for the filters show good agreement with the simulation results.

HTS step-edge Josephson junction terahertz harmonic mixer

A high-temperature superconducting (HTS) terahertz (THz) frequency down-converter or mixer based on a thin-film ring-slot antenna coupled YBa2Cu3O7–x (YBCO)/MgO step-edge Josephson junction is reported. The frequency down-conversion was achieved using higher order harmonics of an applied lower frequency (19–40 GHz) local oscillator signal in the Josephson junction mixing with a THz signal of over 600 GHz, producing a 1–3 GHz intermediate frequency signal. Up to 31st order of harmonic mixing was obtained and the mixer operated stably at temperatures up to 77 K. The design details of the antenna, HTS Josephson junction mixer, the matching and isolation circuits, and the DC and RF performance evaluation are described in this paper.