California Institute of Technology

Sibeam, Inc.

Xiang Guan

Seyed Ali Hajimiri

Abbas Komijani

Arun Sridhar Natarajan

Sohrab Emami-Neyestanak

Chinh Doan

Aydin Babakhani

Hossein Hashemi

Chinh Huy Doan

A circuit features a balun having an unbalanced input and a balanced output, and a differential coupler having a symmetrical structure about a center axis. The differential coupler has a differential input and a differential output, the differential input being coupled to the balanced output of the balun. An impedance element is coupled to a circuit node of the differential coupler at a point along the center axis. Other embodiments are also described and claimed.

Multi-transformer architecture for an active RF circuit

A phased array mm-wave device includes a substrate, a mm-wave transmitter integrated onto the substrate configured to transmit a mm-wave signal and/or a mm-wave receiver integrated onto the substrate and configured to receive a mm-wave signal. The mm-wave device also includes a phased array antenna system integrated onto the substrate and including two or more antenna elements. The phased array mm-wave device also includes one or more dielectric lenses. A distributed mm-wave distributed combining tree circuit includes at least two pairs of differential transconductors with regenerative degeneration and accepts at least two differential input signals. Two mm-wave loopback methods measure the phased array antenna patterns and the performance of an integrated receiver transmitter system.

Mm-wave fully integrated phased array receiver and transmitter with on-chip antennas

A phased-array receiver is adapted so as to be fully integrated and fabricated on a single silicon substrate. The phased-array receiver is operative to receive a 24 GHz signal and may be adapted to include 8-elements formed in a SiGe BiCMOS technology. The phased-array receiver utilizes a heterodyne topology, and the signal combining is performed at an IF of 4.8 GHz. The phase-shifting with 4 bits of resolution is realized at the LO port of the first down-conversion mixer. A ring LC VCO generates 16 different phases of the LO. An integrated 19.2 GHz frequency synthesizer locks the VCO frequency to a 75 MHz external reference. Each signal path achieves a gain of 43 dB, a noise figure of 7.4 dB, and an IIP3 of &#x2212;11 dBm. The 8-path array achieves an array gain of 61 dB, a peak-to-null ratio of 20 dB, and improves the signal-to-noise ratio at the output by 9 dB.

Monolithic silicon-based phased arrays for communications and radars

A radio-frequency amplifier is provided. The radio-frequency amplifier includes a transistor having an input terminal, an output terminal, a control terminal, and a transconductance g. A series-connected feed-through resistance Rand feed-through capacitance Cis connected in parallel with the input terminal and the output terminal of the transistor. A load resistance Ris connected to the output terminal. The control terminal of the transistor is biased at a fixed voltage. Part of the transistor noise follows the looped path through the feed-through resistor instead of passing on to the load, which reduces the noise figure of the amplifier. The value of g, Rand Rare chosen in a way to keep the input impedance of the amplifier matched to a well-defined signal source impedance.

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Pasadena, CA, United States of America

Xiang Guan