Idler Circuit Research Articles

Quantum theory of the dissipative Josephson parametric amplifier

SummaryRecent research in superconducting quantum circuits operating close to the quantum limit results in the need of a quantum mechanical treatment of losses. Of special interest is the dynamic behaviour of an open quantum system. As an example, a negative‐resistance Josephson parametric amplifier is treated. The DC bias voltage is chosen such that a strong interaction between the Josephson junction and the two resonant circuits, the signal and the idler circuit, is achieved. Power exchange occurs between the two considered resonator modes and also between the resonator modes and the DC power supply. Losses in the resonators are modeled by the quantum Langevin method, which describes the losses by coupling the resonators to a heat bath representing a photon gas in thermal equilibrium. The derived dynamic behaviour does not provide signal energy saturation, like classically expected for parametric amplifiers. Introducing a phenomenological multi‐photon coupling approach, saturation of the amplified signal is ensured. The time evolution of the signal and noise energy is calculated and numerically evaluated for a specific example in cases of both, the quantum Langevin method with and without the phenomenological multi‐photon coupling approach. Copyright © 2017 John Wiley & Sons, Ltd.

A fully distributed heterostructure-barrier varactor nonlinear transmission-line frequency multiplier and pulse sharpener

The discrete symmetric heterostructure-barrier varactor (HBV) was previously developed as an unbiased frequency-tripling device that needed no second-harmonic idler circuit. Other work investigated nonlinear transmission lines (NLTLs) employing discrete varactors attached to linear guiding structures. Fully distributed Schottky-varactor NLTLs were excessively lossy. This paper explores NLTLs based on fully distributed HBV structures. Using both a modified finite-difference time-domain method and numerical integration, it is shown that such NLTL's can provide efficient tripling over a wider input bandwidth than is possible with fixed-tuned triplers. It is also demonstrated that the nonlinearity is strong enough for the NLTL to act as a pulse-sharpening device.

Quantum-barrier-varactor diodes for high-efficiency millimetre-wave multipliers

A new device, the quantum-barrier-varactor diode (QBV diode), is proposed for use in multipliers for millimetre waves. Since the capacitance/voltage characteristic is symmetric, only odd harmonics are obtained. Hence there is no idler circuit to consider for the tripler and only one for the quintupler. It is shown that for triplers and quintuplers, the theoretical efficiency using QBVs is comparable or possibly larger than using Schottky varactor diodes.

The Hybrid Parametric Amplifier

This paper calculates the gain and noise performance of a new version of the parametric arnplifier in which the signal circuit is part of an artificial transmission line while the idler circuit is resonant. A particularly useful property of this type of parametric amplifier is absence of oscillation with increasing pump power.

A Wide-Band Parametric Amplmer with Triple-Tuned Signal Circuit and Single-Tuned Idler Circuit (Letters)

It is the purpose of this letter to present the results of the extension of the work of Egami to the case of a single-tuned idler circuit and a triple-tuned signal circuit.

Zero-voltage nondegenerate parametric mode in Josephson tunnel junctions

A new parametric mode in a Josephson tunnel junction biased in the zero-voltage mode is suggested. It is a nondegenerate parametric excitation where the junction plasma resonance represents the input circuit, and a junction geometrical resonance represents the idler circuit. This nondegenerate mode has been observed in analog experiments. In a real junction the realization of this mode of operation depends on the coupling between the plasma resonance and the geometrical resonance, and it is argued that without an external dc magnetic field the even geometrical resonances are most favorable for such a coupling.

A Design Theory for Wide-Band Parametric Amplifiers

A new exact design theory for a nondegenerate parametric amplifier with double-tuned signal circuit and single-tuned idler circuit is described. If the resistance of the signal circuit, which is neglected in previous papers, is considered, there exists a frequency band in which the amplifier gain is positive. In this paper the band characteristics of the gain are related to this frequency band. Slope parameters of the idler and signal circuits are normalized by the slope parameters which are associated with the diode itself. These normalized slope parameters are used to relate the actual circuit and gain-bandwidth characteristics. The slope parameter of the external signal resonator is related to the negative slope parameter of the diode, and bounds on this ratio are given over which stable amplification is possible. A design table which gives the coupling ratio and slope parameter of the external signal resonator is derived by computer calculation. Experiments were made at 19 GHz. Positive-gain bandwidth was around 4.0 GHz, and flat bandwidth at 10-dB gain was 2.4 GHz. The ratio of these bandwidths coincided with the theory.

Very-high-rank avalanche diode frequency multiplier

Recent experimental observations on silicon avalanche diode multipliers operated at about 35-GHz output frequency are presented. High-rank (up to 35) frequency multiplication is achieved with output power over 250 mW and conversion loss of 13 dB. The possibility of frequency multiplication by any integer n ranging from 8 to 35 with the same diode and without any idler circuit is pointed out. It is concluded that any output frequency can be selected between 28 and 39 GHz by varying the input frequency and the circuit tuning.

A Millimeter-Wave Quadruple and an Up-Converter Using Planar-Diffused Gallium Arsenide Varactor Diodes

A millimeter-wave quadruple, employing planar-diffused GaAs varactor diodes and a tuned second-harmonic idler circuit, is described. This quadruple operated at an output frequency of 50.4 GHz, produced a maximum power output greater than 13 mW, and exhibited a maximum overall conversion efficiency of 12 percent. 2) A millimeter-wave up-converter using similar diffused GaAs diodes has been operated successfully. The input was at 1.3 GHz, the output at 51.7 GHz, and the local oscillator power was supplied at 50.4 GHz. The minimum observed overall conversion loss, 50.4 to 51.7 GHz, was about 2.5 dB at an output power between 1 and 3 mW. 3) The performance of these devices is described as a function of the parameters of the diodes employed, and a comparison of the performance of diffused-junction and Schottky-barrier diodes (of comparable quality) in the two circuits is discussed. 4) The fabrication and characterization of the planar-diffused gallium arsenide varactor diodes used in these circuits is described; zero-bias cutoff frequencies to values in excess of 2000 GHz were achieved.

A broad-band parametric amplifier†

This paper describes a broad-band parametric amplifier potentially suitable, for example, as the front amplifier in the ground station receiver of advanced satellite communication systems. A single stage with l0db gain at 4 GHZ has given 20% bandwidth to 033 dB points. The amplifier is capable of cryogenic operation for low noise performance and several stages have been cascaded for higher gain. A novel feature of this amplifier is that it employs an idler circuit with a double peaked response. This approach has led to the development of very simple broad-banding controls which can be adjusted under actual operating conditions even when the amplifiers are refrigerated.

All Solid-State Parametric Amplifier for Broadband Radiolink at 2000 MHz

A microwave amplifier using a varactor diode for improving the receiver noise figure is described. The amplifier is a stable, 2-diode type, with a coaxial signal circuit, a lumped element idler circuit, and a waveguide pump circuit. The design provides a 50-MHz bandwidth at 20-dB gain, and a noise temperature of 200°K. KEYWORDS: Amplifiers, Broadband, Design, Microwave Relay Systems, Signaling, Signal-to-Noise Ratio, Ultra-High Frequency.

Stabilization of the Gain versus Frequency Characteristics of Parametric Amplifiers at High Input Signal Levels

Decreasing the negative bias voltage of varactor diodes in a parametric amplifier causes the gain versus frequency characteristic of the amplifier to shift to the higher-frequency side, resulting in a so-called "positive slope" at the signal center frequency. The same happens when the pump power is increased or when the signal power is increased, but in the latter case only when the idler circuit load resistance is below a certain value. The slope of the gain characteristic can be partially or completely compensated by detuning the signal-circuit characteristic relative to the gain versus freqnency characteristic in such a way that the latter is located on a certain point of the left or right slope of the signal-circuit chara-teristic, or by resistive loading of the idler circuit. Complete cancellation was achieved in the range from -30 to -20 dBm signal input power by using both methods simultaneously on a practical model of a parametric amplifier operating at a signal center frequency of 3.95 GHz and a pump frequency of 11.76 GHz. The loading of the idler circuit was done by drawing a little rectified diode current. The necessary increase in pump power, in order to maintain the same gain as with both signal and idler circuits tuned to resonance, was less than 3 dB, the increase in noise figure a few tenths of 1 dB from a typical value of approximately 3 dB.

The effect of the upper sideband on the performance of a parametric amplifier

The equations which represent the effect of the upper sideband in a conventional parametric amplifier are derived in detail. It is then shown that the effect of the upper sideband is to present a positive conductance to the signal circuit and partly to nullify the negative resistance associated with the idler circuit. The noise figure expression is derived and shows that noise is introduced into the amplifier at the upper sideband and is converted to signal circuit, degrading the noise figure of the amplifier.

Zero-loss second-order ring modulator

It is shown that zero conversion loss may be obtained for the frequency change from ωq to 2ωp ± ωq using an ideal ring modulator switched at a frequency ωp and having a reactive idler circuit at the normal output terminals. The frequency 2 ωp ± ωq is obtained at the normal input terminals, so that advantages are obtained with regard to earthing arrangements.

Maximally Flat Bandwidth of Nondegenerate Parametric Amplifier with Double Tuned Signal Circuit and Single Tuned Idler Circuit (Correspondence)

Maximally Flat Bandwidth of Nondegenerate Parametric Amplifier with Double Tuned Signal Circuit and Single Tuned Idler Circuit (Correspondence)

Paramp with coupled coaxial and waveguide resonators as idler circuit

Paramp with coupled coaxial and waveguide resonators as idler circuit

A high-frequency wideband idler circuit for parametric amplifiers

A high-frequency wideband idler circuit for parametric amplifiers

Maximum Bandwidth Performance of Non- degenerate Parametric Amplifier with Single-Tuned Idler Circuit

The single-tuned bandwidth and limiting flat bandwidth of a nondegenerate reflection-type diode parametric amplifier is calculated. The amplifier has a broad-banding filter structure in the signal circuit and a single-tuned idler circuit. An experimental low-noise, wide-band Z-band amplifier is described, and measurement results are presented. The amplifier has a triple-tuned signal circuit and a single-tuned idler circuit and is pumped at 11.3 Gc. A nearly flat bandwidth of 23 per cent at 7 db gain and an effective input noise temperature of 70/spl deg/K at room temperature ambient and of 29/spl deg/K at liquid nitrogen (77/spl deg/K) ambient has been obtained.

A broadband balanced idler circuit for parametric amplifiers

The bandwidth of the idler circuit of a parametric amplifier is discussed, and reductions in bandwidth associated with stray reactances of the diode encapsulation and filter networks required to complete the idler circuit are described. A balanced idler circuit using two diodes is shown to approach the theoretically maximum idler bandwidth. A 3000 Mc/s amplifier is described having a 10% bandwidth at 20 dB gain.

A parametric amplifier with double-tuned idler circuit

A parametric amplifier with double-tuned idler circuit