GHz Sub-harmonic Mixer Research Articles

A 60 GHz Sub-Harmonic Resistive FET Mixer Using 0.13 $\mu{\rm m}$ CMOS Technology

A 56 to 66 GHz sub-harmonic resistive mixer using 0.13 μm CMOS technology is presented in this letter. This mixer exhibits a flat conversion loss of about -12 and -13 dB and good isolations between ports from 56 to 66 GHz for both down and up-conversion with a lowest LO power of 0 and -1 dBm. The 2LO-RF isolation is more than 27 dB even if IF input power exceeds 4 dBm, which results from the mechanism of connecting drain and body of the device. Besides, this mixer has a relatively high input <i xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">P</i> <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">1dB</sub> and a 3 GHz IF bandwidth in each band defined in IEEE 802.15.3c standard.

A Miniaturized Monolithic 18–40 GHz Sub-harmonic Mixer

In this paper, a miniaturized 18–40 GHz sub-harmonic mixer is designed and implemented with 0.15 μm GaAs pHEMT process. The proposed mixer employs anti-parallel diode pair with parallel to ground configuration, and a novel coupler structure to feed RF and LO signals, resulting in broadband performance and compact chip size. The measured conversion loss is 10.3–13.5 dB in a wide operation frequency band of 18–40 GHz. The chip size is 0.66 mm2.

V-BAND HIGH ISOLATION SUBHARMONIC MONOLITHIC MIXER WITH HAIRPIN DIPLEXER

A 54{66GHz sub-harmonic monolithic passive mixer using the standard 0.15m pHEMT process is demonstrated. The proposed mixer is composed of a hairpin diplexer, an open stub, and a low-pass fllter. The mixer also utilizes a pair of anti-parallel diodes to achieve a subharmonic mixing mechanism. The hairpin diplexer formed with two parallel-coupled line band-pass fllters is used to improve the isolation between the radio frequency (RF) and local oscillation (LO) ports. The low-pass fllter supports an intermediate frequency (IF) ranging from dc to 1GHz. This proposed conflguration leads to a die size of less than 1.5mm 2 . With a conversion loss of 15.2{18.3dB, the 2LO- to-RF isolation is found to be better than 27.5dB. A high LO-to-RF isolation of 23.5{45dB over 54{66GHz RF bandwidth, as well as 1dB compression power of 8dBm, can be achieved.

A 320–360 GHz Subharmonically Pumped Image Rejection Mixer Using Planar Schottky Diodes

This letter presents the design, fabrication and test of an integrated 320-360 GHz subharmonic image rejection mixer using planar Schottky diodes. The integrated circuit uses two separate anti-parallel pairs of diodes mounted onto a single quartz-based circuit. Measurement results give best single sideband (SSB) receiver noise temperatures of approximately 3400 K at 340 GHz, with an image rejection from 7.2 to 24.1 dB over the 320-360 GHz frequency band. This work represents the first demonstration of a Schottky based SSB mixer at submillimeter wavelengths.

A Combined 380 GHz Mixer/Doubler Circuit Based on Planar Schottky Diodes

The design, fabrication and test of a combined sub-millimeter wave mixer/doubler featuring a 380 GHz sub-harmonic mixer and a 190 GHz frequency doubler on a single quartz based microstrip circuit is reported in this letter. The integrated circuit uses separate flip-chip mounted planar Schottky diode components to perform the two functions. Measurements give best double sideband mixer noise temperatures of 1625 K at 372 GHz, and a corresponding mixer conversion loss of 8 dB. The measured fixed-tuned radio frequency bandwidth extends from 368 to 392 GHz, in good agreement with simulations. This work represents the first demonstration of a single substrate combined submillimeter wave mixer/doubler.

Design of low-cost 183 GHz subharmonic mixers for commercial applications

Techniques are presented for designing fixed-tuned millimetre-wave components with the least number of parts to minimise the cost and maximise the potential for volume manufacture. Design techniques for millimeter-wave mixer components targeted at potentially high volume applications, such as medical and security screening and nondestructive testing, require certain compromises in the use of CAD tools. The compromise techniques are demonstrated using commercially available foundry diodes in the design of a 183 GHz subharmonic mixer for earth observation applications. The resulting mixer exhibits 6.85 dB double sideband conversion loss and a mixer temperature of 988 K using 5 mW of local oscillator power at 92 GHz.

A 77 GHz SiGe sub-harmonic balanced mixer

A novel SiGe 77 GHz sub-harmonic balanced mixer is presented with a goal to push the technology to its limit [SiGe2-RF transistor (f/sub T/=80 GHz)]. This new topology uses a compact input network not only to achieve high isolation between the LO and RF ports, but also to result in excellent 2LO-RF isolation. The measured results demonstrate a conversion gain of 0.7 dB at 77 GHz with an LO power of 10 dBm at 38 GHz, LO-RF isolation better than 30 dB, 2LO-RF isolation of 25 dB, and a P/sub 1dB/ of -8 dBm. The mixer core consumes 4.4 mA at 5 V. The circuit demonstrates that SiGe sub-harmonic mixers have comparable performance with GaAs designs, at a fraction of the cost.

Two-dimensional correlation measurements of electron cyclotron emission fluctuations on the stellarator Wendelstein 7-AS

The miniaturization of receiver arrays permits the arrangement of numerous poloidally staggered radial sightlines of an electron cyclotron emission (ECE) diagnostic for the measurement of the electron temperature and its fluctuations, making two-dimensional (2D) imaging of the electron temperature and its fluctuations caused by plasma turbulence possible. For the stellarator W7-AS, the development of a fully monolithic microwave integrated circuit 150 GHz subharmonic mixer array is under development. As a first step, a 2D ECE system for the measurement of electron temperature fluctuations using four individual horn-reflector arrangements in conjunction with multichannel heterodyne radiometers was installed and set into operation. With Gaussian beam optics and four poloidally staggered sightlines, electron temperature fluctuations could be characterized in radial and poloidal directions simultaneously. First observations in purely electron cyclotron resonance heated stellarator plasmas reveal a broadband drift-wave feature. Earlier experiments showing a decrease of the electron temperature fluctuation level with increasing heating power were confirmed. Additionally, it was revealed, using the 2D ECE correlation radiometer, that an increased velocity shear might account for the decrease of the coherence length and thus for the reduction of the electron temperature fluctuation level.

Subharmonic waveguide mixer at 215 GHz utilizing quasivertical Schottky diodes

The design of a 215 GHz subharmonic waveguide mixer utilizing an antiparallel pair of quasivertical Schottky diodes is presented. The impedance matching is provided by series and parallel waveguide tuners. A single sideband noise temperature of 3500 K and conversion loss of 9.2 dB have been measured (antenna loss included). © 2000 John Wiley & Sons, Inc. Microwave Opt Technol Lett 27: 93–97, 2000.