Wasif Tanveer Khan

A 60-GHz Active Receiving Switched-Beam Antenna Array With Integrated Butler Matrix and GaAs Amplifiers

This paper presents for the first time a 60-GHz receiving switched-beam antenna on organic liquid crystal polymer (LCP) platform. A 4 × 1 quasi-Yagi array is incorporated with a 4 × 4 Butler matrix beamforming network and GaAs low-noise amplifiers on an LCP substrate. The active beam is controlled by GaAs single-pole-double-throw switches to access the four output states of the Butler matrix. The entire 4 × 1 active array is 1.4 cm × 1.75 cm and consumes 1.1 W of dc power. Successful comparisons of the measured and simulated results verify a working phased array with a return loss better than 10 dB across the frequency band of 56.7-63.7 GHz. A comparison of radiation patterns demonstrate beam steering of ±40° with a peak active gain of 27.5 dB. The combined antenna and receiver noise performance at 60 GHz exhibits an estimated merit G/T of -18.6 dB/K and noise figure of 5.4 dB.

Packaging a

This paper, for the first time, presents successful integration of a W-band antenna with an organically flip-chip packaged silicon-germanium (SiGe) low-noise amplifier (LNA). The successful integration requires an optimized flip-chip interconnect. The interconnect performance was optimized by modeling and characterizing the flip-chip transition on a low-loss liquid crystal polymer organic substrate. When the loss of coplanar waveguide (CPW) lines is included, an insertion loss of 0.6 dB per flip-chip-interconnect is measured. If the loss of CPW lines is de-embedded, 0.25 dB of insertion loss is observed. This kind of low-loss flip-chip interconnect is essential for good performance of W-band modules. The module, which we present in this paper, consists of an end-fire Yagi-Uda antenna integrated with an SiGe BiCMOS LNA. The module is 3 mm × 1.9 mm and consumes only 19.2 mW of dc power. We present passive and active E- and H-plane radiation pattern measurements at 87, 90, and 94 GHz. Passive and active antennas both showed a 10-dB bandwidth of 10 GHz. The peak gain of passive and active antennas was 5.2 dBi at 90 GHz and 21.2 dBi at 93 GHz, respectively. The measurements match well with the simulated results.

W

A single-pole double-throw switch, utilizing double-shunt, deep-saturated HBTs is implemented in a 0.13 μm SiGe BiCMOS technology, occupying 0.36 mm2 of IC area. A superior switch performance is identified when HBTs are operated in saturation regime, and state of the art performance is achieved at D-band frequencies from 96 to 163 GHz. Measurements show a minimum insertion loss of 2.6 dB at 120 and 150 GHz, a highest isolation of 29 dB at 120 GHz and an input 1 dB compression point of 17 dBm at 94 GHz, outperforming similar implementations in deep-scaled CMOS technologies.

-Band Integrated Module With an Optimized Flip-Chip Interconnect on an Organic Substrate

In this paper, for the first time, characterization of planar transmission lines on organic Liquid Crystal Polymer (LCP) substrate in D-Band is presented. Via-less conductor backed co-planar wave guide (CB-CPW) and microstrip lines are designed, fabricated and measured on 2 mil organic LCP substrate. Line-reflect-reflect-match (LRRM) calibration technique was used to measure the fabricated lines, whereas in order to accurately extract line loss and to characterize the substrate, a thru-reflect-line (TRL) calibration was performed. The results have shown excellent RF performance of LCP in the D-band, while the microstrip line exhibits a loss of 0.1755 dB/mm at 110 GHz, with a monotonous increase to 0.331dB/mm at 170 GHz. An almost constant (~2.6) effective dielectric constant is also reported within the whole measurement band.

A Low-Loss and High Isolation D-Band SPDT Switch Utilizing Deep-Saturated SiGe HBTs

In this paper, aerosol jet printing technology is assessed for D-band RF applications for the first time. It describes the fabrication process, the technology assessment and the characterization of coplanar waveguides (CPW) lines and CPW to microstrip transitions on liquid crystal polymer (LCP) in the D band using silver nanoparticle aerosol jet printing process. Feature sizes with a resolution of 10 μm, which is the finest resolution among all of the digital printing technologies, were realized successfully. The conductivity of the sintered silver structures was half to that of bulk silver after sintering at temperatures up to 200 °C. Printed transmission lines demonstrated losses of 0.35 dB/mm at 110 GHz and 0.51 dB/mm at 170 GHz that are less than that of the insertion loss of the inkjet printing lines by an order of magnitude.

D-Band characterization of co-planar wave guide and microstrip transmission lines on liquid crystal polymer

In this paper, the Polyjet technology was applied to build high-Q X-band resonators and low loss filters for the first time. As one of state-of-the-art 3-D printing technologies, the Polyjet technique produces RF models with finest resolution and outstanding surface finish in a clean, fast and affordable way. The measured resonator with 0.3% frequency shift yielded a quality factor of 214 at 10.26 GHz. A Vertically stacked two-cavity bandpass filter with an insertion loss of 2.1 dB and 5.1% bandwidth (BW) was realized successfully. The dimensional tolerance of this process was found to be less than 0.5%. The well matched performance of the resonator and the filter, as well as the fine feature size indicate that the Polyjet process is suitable for the implementation of low loss and low cost RF devices.

High resolution aerosol jet printing of D- band printed transmission lines on flexible LCP substrate

We present a 314 GHz transmitter and receiver chipset which is implemented in an advanced SiGe HBT platform, and which has on-chip antennas. The transmitter uses an active antenna structure, where the generated on-chip signal is directly fed into the antenna. The receiver consists of a novel sub-harmonic resistive mixer with an on-chip high-power differential signal source feeding the LO port. A test link which directly connects the transmitter to the receiver was also implemented as a reference for characterization. This reference circuit enables a simple and accurate measurement method for conversion loss and antenna gain by omitting external high frequency signal sources. To further facilitate the characterization, the utilized on-chip signals were implemented and tested separately as well. The receiver achieves 22.5 dB conversion loss and the transmitter generates a signal power of -8 dBm at 314 GHz. On-die end-fire antennas were designed for both transmit and receive paths, and utilize a substrate etching technology to boost performance. This work demonstrates the feasibility of fully-integrated and compact sub-mmW transceiver implementations using SiGe technology.

A low loss X-band filter using 3-D Polyjet technology

This paper presents, for the first time, a tunable microstrip microfluidic bandpass filter, with a center frequency of 1 GHz, on liquid crystal polymer (LCP). A 60 mil cavity, initially filled with distilled (DI) water (εr = 80), is placed below a 2 mil LCP layer. Based on this multilayer structure, the dimensions of microstrip lines are determined. In order to tune the filter center frequency, DI water is replaced by acetone, with a dielectric constant that is 4 times lower than that of DI water (εr = 20.7). A micropump is used to inject the different fluids and provide the necessary pressure to trap the liquid inside the microfluidic channel. Measured results show 50% tuning which translates into a maximum center frequency shift of 500 MHz. The insertion loss is 1.4 dB and the return loss is 25 dB at 1 GHz for the DI water filter while the insertion loss is 1.3 dB and the return loss is 15.8 dB at 1.5 GHz for the acetone filter.

A 314 GHz, fully-integrated SiGe transmitter and receiver with integrated antenna

Liquid crystal polymer is a promising substrate for mm-wave packaging. In this work, we present the characterization of liquid crystal polymer from 110 GHz to 170 GHz. The microstrip ring resonator method is used for the relative permittivity and loss tangent extraction at mm-wave frequencies. The effect of radiation loss in the extraction of loss tangent is analyzed through full electromagnetic 3D models to verify that radiation loss can be neglected for the particular geometry under study. The Monte Carlo uncertainty analysis is used to analyze the uncertainty of the method taking into account the uncertainty of each measurement involved in the characterization. Using a frequency dispersive model for the effective permittivity for the microstrip, the relative permittivity of LCP is extracted to be 3.17 and the loss tangent varies from 0.0055 to 0.009. This work is the first to characterize the liquid crystal polymer in D-band.

L-band tunable microstrip bandpass filter on multilayer organic substrate with integrated microfluidic channel

In this paper, a fully packaged D-band MIMO phased-array transmitter using system-on-package (SoP) technology is presented. The transmitter chip is implemented in a 32nm CMOS SOI process and assembled on the liquid crystal polymer (LCP) substrate by flip-chip interconnects. The MIMO operation is enabled by an on-chip transformer based 4×4 Butler Matrix. The package fabrication realizes a consistent minimum feature size of 20μm on a 2-mil flexible LCP substrate. Moreover, the CMOS chip with a total of 72 RF and DC pads is well aligned with and successfully bonded onto the corresponding patterns on the LCP package. The capability of package fabrication with fine features and high-density chip-to-package interconnections enables the implementation of cost-effective and high-performance hybrid complex systems at mm-wave. Measurement results based on probing demonstrate the functionalities of the entire system.