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This paper presents a novel 90 GHz band 16-quadrature amplitude modulation (16-QAM) orthogonal frequency-division multiplexing (OFDM) communication system. The system can deliver 6 Gbps through six channels with a bandwidth of 3 GHz. Each channel occupies 500 MHz and delivers 1 Gbps using 16-QAM OFDM. To implement the system, a low-noise amplifier and an RF up/down conversion fourthharmonically pumped mixer are implemented using a 0.1-μm gallium arsenide pseudomorphic high-electronmobility transistor process. A polarization-division duplex architecture is used for full-duplex communication. In a digital modem, OFDM with 256-point fast Fourier transform and (255, 239) Reed-Solomon forward error correction codecs are used. The modem can compensate for a carrier-frequency offset of up to 50 ppm and a symbol rate offset of up to 1 ppm. Experiment results show that the system can achieve a bit error rate of 10-5 at a signal-to-noise ratio of about 19.8 dB. [ABSTRACT FROM AUTHOR]

This paper presents a novel 16-quadrature-amplitude- modulation (QAM) E-band communication system. The system can deliver 10 Gbps through eight channels with a bandwidth of 5 GHz (71-76 GHz/81-86 GHz). Each channel occupies 390 MHz and delivers 1.25 Gbps using a 16-QAM. Thus, this system can achieve a bandwidth efficiency of 3.2 bit/s/Hz. To implement the system, a driver amplifier and an RF up-/down-conversion mixer are implemented using a 0.1 µm gallium arsenide pseudomorphic high-electron-mobility transistor (GaAs pHEMT) process. A single-IF architecture is chosen for the RF receiver. In the digital modem, 24 square root raised cosine filters and four (255, 239) Reed-Solomon forward error correction codecs are used in parallel. The modem can compensate for a carrier-frequency offset of up to 50 ppm and a symbol rate offset of up to 1 ppm. Experiment results show that the system can achieve a bit error rate of 10-5 at a signal-to-noise ratio of about 21.5 dB. [ABSTRACT FROM AUTHOR]

this paper, the implementations of a 0.1 µm 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. [ABSTRACT FROM AUTHOR]

We present the design and fabrication of power amplifier (PA) and low noise amplifier (LNA) in 60 GHz using 90 nm CMOS process. Both of them have three stages topology. We obtained small signal gain of 21 dB, p1dB of 4 dBm, and input/output return losses of <−9 dB in PA. We also obtained small signal gain of 25 dB, noise figure of <7 dB, p1dB of 1.5 dBm, input/out return losses of <−8 dB in LNA. The die sizes of PA and LNA are 1.1 × 0.8 mm2 and 0.59 × 0.78 mm2, respectively. Both sizes contain the RF pads and bias pads. Especially, the size of LNA is reduced by using hairpin type matching structure. © 2009 Wiley Periodicals, Inc. Microwave Opt Technol Lett 51: 2029–2032, 2009; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/mop.24549 [ABSTRACT FROM AUTHOR]

A parabolic reflector antenna with an azimuthally deformed Cassegrain subreflector is proposed to effectively generate arbitrary orbital angular momentum (OAM) modes. The Cassegrain dual-reflector antenna was fabricated for 18 GHz and measured in the near-field range. The near-field to far-field transformed radiation phase around a full azimuth shows that the proposed antenna generates fields with the l = 1 OAM mode. Simulated and measured feed reflection coefficients are below -- 10 dB for 15.1--21.2 GHz, even though the distance between a horn feed and a deformed subreflector is 15.6 mm, thus it is expected that the proposed structure can be used for a broadband low-profile antenna. [ABSTRACT FROM AUTHOR]