Yi-Long Chang

60-GHz Four-Element Phased-Array Transmit/Receive System-in-Package Using Phase Compensation Techniques in 65-nm Flip-Chip CMOS Process

AThe 60-GHz four-element phased-array transmit/receive (TX/RX) system-in-package antenna modules with phase-compensated techniques in 65-nm CMOS technology are presented. The design is based on the all-RF architecture with 4-bit RF switched LC phase shifters, phase compensated variable gain amplifier (VGA), 4:1 Wilkinson power combining/dividing network, variable-gain low-noise amplifier, power amplifier, 6-bit unary digital-to-analog converter, bias circuit, electrostatic discharge protection, and digital control interface (DCI). The 2 × 2 TX/RX phased arrays have been packaged with four antennas in low-temperature co-fired ceramic modules through flip-chip bonding and underfill process, and phased-array beam steering have been demonstrated. The entire beam-steering functions are digitally controllable, and individual registers are integrated at each front-end to enable beam steering through the DCI. The four-element TX array results in an output of 5 dBm per channel. The four-element RX array results in an average gain of 25 dB per channel. The four-element array consumes 400 mW in TX and 180 mW in RX and occupies an area of 3.74 mm2 in the TX integrated circuit (IC) and 4.18 mm2 in the RX IC. The beam-steering measurement results show acceptable agreement of the synthesized and measured array pattern.

LTCC Layer-to-Layer Misalignment-Tolerant Coupled Inductors and Their Application to Bandpass Filter and Helical Inductors

Mutual inductance between coupled inductors can provide large equivalent series inductance required by filter design. As mutual inductance is dependent on the distance between coupled metal lines within coupled inductors, mutual inductance in traditional straight line coupled inductors (SLCI) is susceptible to layer-to-layer misalignment during fabrication if two coupled lines are located at different substrate layers. Misalignment-tolerant coupled inductors (MaTCI) are proposed to alleviate the effect of misalignment on mutual inductance. Circuit model is also proposed to describe their mechanism. Their performance is verified and compared with traditional SLCI using coupled inductors based transmission zero circuits and bandpass filters. Measurement results of three samples of a transmission zero circuit based on proposed MaTCI show only 0.56% frequency variation at 1.9 GHz, while traditional SLCI give about 3.2% variation from samples at the same low temperature cofired ceramic substrate. Measured results of three samples of a bandpass filter using MaTCI also show more stable performance at transmission zero frequency, insertion loss and passband bandwidth as compared with the filter using traditional SLCI. Electromagnetic simulation also shows similar performance improvement for MaTCI under misalignment. The same concept is also applied to helical inductor and two misalignment tolerant helical inductors are proposed. Simulation results show that they are more stable than the traditional stacked helical inductor.

Dual-band CRLH branch-line coupler in LTCC by lump elements with parasite control

The capacitance of a rectangle MIM capacitor is mainly controlled by its over-lapping area, while its aspect ratio can control the amount of parasitic inductance. With these two parameters, we can achieve both capacitance and parasitic inductance simultaneously. To achieve inductance and parasitic capacitance of a shunt spiral inductor at the same time, we add slot at ground plane to control the amount of shunt capacitance with spiral inductor size to control inductance. With these layout strategies, we can realize CRLH transmission lines in LTCC for dual band branch-line coupler with only series MIM capacitor and shunt spiral inductor in layout. Measurement results show dual-band coupling responses at 2.4GHz and 5.2 GHz and agree well with simulation.

Embedded end-fire monopole antenna in low temperature cofired ceramic for 60 GHz

A monopole antenna embedded in low temperature cofired ceramic (LTCC) for end-fire radiation is presented in this paper. It provides horizontal polarization at 60 GHz band for short range high speed data communication. The antenna is embedded at edge of an LTCC substrate for end-fire radiation. The size of the antenna without feeding structure is 2.5mm(W) × 1.0mm(D) × 1.38mm(H) and embedded in a substrate of 2.8mm(W) × 2.44mm(D) × 1.38mm(H). The measured -10dB input matching bandwidth is 62~65GHz. Simulation results show about 4.7dB gain and 3dB beamwidth of 85 degree and 125 degree at horizontal and vertical plane.

Lump devices mapping between designer's schematic and layout extracted schematic in microwave frequency

This paper presents an algorithm that can compare the net-lists between schematic and layout of passive microwave multi-layer circuits. Weight vectors that are related to inductance and capacitance of devices connected to a node are defined for node mapping. However, due to the symmetry of microwave circuits, many possible mapping may be found. We then developed a scoring policy to find the most similar mapping. This checker can help designers to verify layout by comparing the net-list from designers schematic and net-list extracted from layout. This algorithm can also provide missing and extra devices in net-list to assist designer to allocate layout errors quickly.