Critical Temperature Dependence of High Frequency Electron Dynamics in Superconducting Hot-Electron Bolometer Mixers Irfan Siddiqi May, 2002 Superconducting diffusion-cooled hot-electron bolometer (HEB) mixers are ideal candidates for use in terahertz heterodyne spectroscopy (THz). This thesis investigates mixer performance as a function of the superconducting transition temperature (Tc). In th...

We report on microwave measurements of superconducting aluminum hot-electron bolometers (Al HEBs). Diffusion-cooled Al HEB mixers are ideal candidates for space-borne and terrestrial remote-sensing applications in the Terahertz frequency range since they are predicted to have small local oscillator (LO) power requirements, intermediate frequency (IF) bandwidths ! 10 GHz, and a noise temperature...

A self-heterodyne diode mixer is proposed using thin film process based on alumina substrate at 60 GHz in conjunction with grounded coplanar waveguide transition. To down-convert both very low RF and LO signals received simultaneously from transmitter for self-heterodyne communication scheme, the proposed mixer adapted with the knee voltage bias condition of 0.65 [V] improves its mixing efficie...

2014 We have used a Josephson junction to investigate the spectral purity of an HCN laser which is used in an infrared frequency synthesis chain. To obtain a narrower linewidth from the laser it has been phase locked to a multiplied microwave reference chain. A calculated value for this linewidth was based upon the measured noise spectrum of the microwave source and a theory due to Middleton. O...

A compact reconfigurable photonic microwave mixer is proposed and demonstrated based on a dual-polarization Mach-Zehnder modulator and an optical 90-deg hybrid. By simply changing the photodetection schemes, single-ended, double-balanced, I/Q, and image-reject mixing can be implemented. Thanks to the sidebands selection by an optical filter, unwanted mixing spurs are highly suppressed. In addit...

The theory of noise and conversion loss in millimeterwave mixers, developed in a companion paper, is applied to an 80-120.-GHz mixer. Good agreement is obtained between theoretical and experimental results, and the source of the recently reported “anomalous noise” is explained. Experimental methods are described for measuring the embedding impedance and diode equivalent circuit, needed for the ...

The analysis of crosstalk between ports of integrated balanced mixers is difficult because the circuit is strongly nonlinear and the crosstalk depends on information which, if it is known at all, is not always provided by the foundry. This paper presents a general method for calculating mixer crosstalk. Device measurements are combined with periodic small-signal analysis to yield the crosstalk ...