Sub-harmonically Pumped Mixer Research Articles

A Phase Conjugator Based on Fourth-Order Subharmonically Pumped Mixers

A Phase Conjugator Based on Fourth-Order Subharmonically Pumped Mixers

A GaN-on-Si passive upconversion mixer for Ku-band applications

This paper showcases a passive single side-band (SSB) subharmonically pumped (SHP) GaN on Si mixer intended for operation in the Ku band. A passive topology has been selected in order to test the viability of these kinds of designs for GaN applications. By utilising the SSB SHP mixer, it is possible to reduce the energy consumption of a complete transmission system implementation. Two techniques to enhance the performance of the mixer are tested. First, the quasi-lumped method has been employed to reduce the size of the stubs needed to implement the mixer topology. Secondly, octagonal tapered inductors were used to obtain higher quality factors and narrow the frequency response of the lumped-element hybrids. The final design occupies an area of 2720μm×1514μm, including pads. Measurements show a performance in line with the simulations, with a slight increase in its losses with respect to the simulation results. Through the measurement of a transistor of the technology, it is demonstrated that this deviation is caused by the variability of the process and its low technology readiness level (TRL). The results are very promising and prove the advantages of implementing passive mixers for high-frequency applications in GaN on Si technologies.

V-Band High Data-Rate I/Q Modulator and Demodulator With a Power-Locked Loop LO Source in 0.15-/spl mu/m GaAs pHEMT Technology

A wideband sub-harmonically pumped (SHP) modulator and demodulator fabricated in 0.15-μm GaAs pseudomorphic high electron-mobility transistor technology are demonstrated in this paper. The chip is appropriate for emerging 60-GHz multi-gigabit communication applications. Digital modulation degradation resulting from in-phase/quadrature mismatch is effectively minimized by the proposed power-locked loop system. By overcoming the bandwidth limitations and quadrature errors in amplitude and phase, the sideband suppression ratio exhibits broadband performance with the feedback mechanism. By using the SHP mixer structure, the dc offset problem is mitigated because of decreased 2× local oscillator leakage. In addition, sub-circuit design considerations and feedback stability are described in this paper. The SHP modulator and demodulator demonstrate flat conversion-gain responses of -14 ±2 dB and -14 ±1 dB, respectively, from 51 to 68 GHz. Properties of multi-gigahertz modulation and demodulation bandwidths show the potentials for gigabit applications. The amplitude and phase imbalances are restricted within 0.3 dB and 5° (±2.5°), respectively, regardless of modulation or demodulation. High data-rate digital modulation and demodulation are successfully performed through 16-QAM and 64-QAM schemes within four channels of the IEEE 802.15.3c standard with outstanding error vector magnitude performances.

E-Band Wideband MMIC Receiver Using 0.1 µm GaAs pHEMT Process

In this paper, the implementations of a gallium arsenide (GaAs) pseudomorphic high electron mobility transistor process for a low noise amplifier (LNA), a subharmonically pumped (SHP) mixer, and a single-chip receiver for 70/80 GHz point-to-point communications are presented. To obtain high-gain performance and good flatness for a 15 GHz (71 GHz to 86 GHz) wideband LNA, a five-stage input/output port transmission line matching method is used. To decrease the package loss and cost, 2nd and 4th SHP mixers were designed. From the measured results, the five-stage LNA shows a gain of 23 dB and a noise figure of 4.5 dB. The 2nd and 4th SHP mixers show conversion losses of 12 dB and 17 dB and input P1dB of -1.5 dBm to 1.5 dBm. Finally, a single-chip receiver based on the 4th SHP mixer shows a gain of 6 dB, a noise figure of 6 dB, and an input P1dB of -21 dBm.

Size Reduction of a MMIC Direct Up-Converter at 44 GHz in Multilayer CPW Technology Using Thin-Film Microstrip Stubs Loading

This paper proposes a novel compact multilayer 44.5-GHz coplanar waveguide (CPW) single-sideband (SSB) subharmonically pumped (SHP) mixer for direct up-conversion GaAs monolithic microwave integrated circuit. It uses previously developed thin-film microstrip (TFMS) and CPW structures for capacitive and inductive loading techniques to drastically reduce its size. The SSB SHP mixer uses 50-MHz in-phase and quadrature signals to directly modulate the second harmonic of a 22.25-GHz carrier to produce the required 44.55-GHz RF output. Two pairs of antiparallel diodes reduce feedthrough of the fundamental 22.25-GHz signal to the RF output while novel CPW/TFMS-based structures provide matching. This 1.2times1.5 mm <sup xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">2</sup> chip uses a lumped Wilkinson divider as a local-oscillator divider and a previously developed reduced size 90deg coupler. The SSB SHP mixer acts as an up-converter with a measured conversion gain of -10plusmn1 dB and the lower sideband suppression is greater than 23 dB across the RF bandwidth of 43.5-45.5 GHz. Additionally, it is shown that the RF port return loss is better than 20 dB, and 2timesf <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">LO</sub> was suppressed by 21 dB over the same band. The circuit also does not require any dc bias. Compared to the conventional SSB SHP mixer, a 70% reduction in circuit area was achieved with better performances

Dual-band sub-harmonic quadrature mixer using composite right∕left-handed transmission lines

A dual-band (DB) sub-harmonic quadrature mixer using composite right/left-handed (CRLH) transmission lines (TL) is presented. The CRLH-TLs are used to provide dual-bandwidth operation in the Wilkinson power dividers (WPDs), the ±45° delay line for in-phase/quadrature generation, and the sub-harmonically pumped mixers. Theory and implementation of the RF/LO DB-WPDs, the dual-passband dual-stopband (DPDS) shunt terminations, and the DB sub-harmonically pumped mixers (SHPMs) are presented. These DB microwave components for the DB quadrature mixer are detailed in individual sections with both simulated and measured performances. The DB-WPDs exhibit S21 and S31 larger than −3.95 dB, return losses larger than 12 dB, isolations larger than 16 dB, phase imbalance less than 2.15°, and gain imbalance less than 0.25 dB at each passband. The DPDS terminations demonstrate insertion loss larger than 16 dB at stopbands and less than 2.3 dB at passbands. The DB-SHPM shows 10 dB and 11.7 dB conversion loss in low- and high-frequency mixing schemes with good linearity. Local oscillator (LO) to radio frequency (RF) isolation larger than 30 dB is also measured in both frequency mixing schemes. The measured results of the DB quadrature mixer display output amplitude balance, orthogonal characteristic, and LO to RF isolation larger than 45 dB.

Novel subharmonically pumped mixer incorporating dual-band stub and in-line SCMRC

A subharmonically pumped (SHP) mixer with very low conversion loss is proposed. The mixer employed the newly developed spiral compact microstrip resonant cell (SCMRC) and compact dual-band stub (DBS). Incorporating the in-line SCMRC and DBS into a second SHP mixer, we can provide proper terminations for the IF, RF, and local-oscillator (LO) signal simultaneously in addition to all major unwanted mixing products, leading to a unique low conversion-loss design. Our SHP mixer with a measured 3.9-dB single-sideband (SSB) down-conversion loss at 11.6-GHz RF signal outperforms typical designs of 8-12 dB, and represents a state-of-the-art performance for a planar X-band harmonic mixer. With a broad-band operation, our mixer shows an SSB down-conversion loss of less than 8.2 dB from 9 to 12.8 GHz. Moreover, the measured LO-RF isolation is better than 45 dB for LO frequency ranges of 4-5.8 GHz. Large-signal two-tone measurements reveal an excellent linear response of the working prototype, showing 7.5 dBm and 52 dB for the 1- dB power compression point and spurious-free dynamic range, respectively.