Aida L. Vera Lopez

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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.

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A new geometry-based channel model is proposed for wide-band polarized body-area-network channels consisting of four propagation modes, i.e., cylindrical surface scattering (CSS) for above-ground off-body scattering (BS), BS for body diffracted and on-BS, ground scattering (GS), and line-of-sight. A conservation-of-polarization plane methodology is used for the CSS and GS propagation modes. For the BS propagation mode, a geometrical theory of diffraction is used and related to CSS. The channel cross-polarization discrimination (XPD) and time-frequency correlation function (TF-CF) are derived from the model. Comparisons of the XPD and the TF-CF that are obtained from the model (with appropriate physical parameters) and those obtained from wide-band measurements at 13-GHz are in good agreement. We observed the GS propagation mode to be the dominant mode in our experiments. The azimuth angle of arrival (AAoA) of a ground reflected wave is shown in theory to have a significant effect on the XPD.

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

RXP is a novel and emerging low loss thin core experimental material that has shown promising results as an RF dielectric substrate. In this paper, Ring Resonator Method was utilized to characterize its dielectric properties (relative permittivity and loss tangent) from 30 to 70 GHz frequency domain. BT, a PCB compatible substrate, and RO3003™, an RF organic material, were also characterized for the purpose of comparison. The measured dielectric constant for RXP4 is found to be stable near 3.13, and the loss tangent remains below 0.005. For RXP1, the dielectric constant averages 4.2, and its loss tangent stays below 0.01. To verify application of RXP at higher frequencies, an aperture-coupled patch antenna was designed at 60 GHz and fabricated using three metal layers. The performance of the antenna was found to be comparable to that of Liquid Crystal Polymer (LCP) substrate. The achieved bandwidth was ~3 GHz, and the gain was around 4.7 dBi (simulation results). The measured bandwidth on the fabricated antenna was ~2 GHz. These results show for the first time that RXP can be a good candidate material for wireless 60 GHz application.

Geometrically Based Statistical Model for Polarized Body-Area-Network Channels

In this paper, we present a novel Fourier technique to calculate the emitter-to-fiber coupling efficiency between an incoherent source of arbitrary directivity and a multimode fiber. The technique expresses the 4-D integral that describes the coupling as a 2-D sum, and along with Fourier series expansion, the technique increases greatly the computational speed of emitter-to-fiber coupling calculations. We have simulation results of the emitter-to-fiber coupling analysis and coupling analysis for a single-fiber bi-directional link total using the Fourier technique. The results show that the large core plastic optical fiber gives rise to good emitter-to-fiber coupling alignment tolerance, but tends to overfill the detector and cause degradation in fiber-to-detector alignment tolerance. We find that a more directive resonant-cavity light emitting diode only improves emitter-to-fiber alignment tolerance slightly, though it can couple more light into the fiber.

Novel low loss thin film materials for wireless 60 GHz application

This paper presents for the first time a hybrid silicon-organic packaged mm-wave antenna, that is flip-chip bonded to a 400 µm thick silicon substrate through gold bumps and a non-conductive film (NCF) adhesive layer. The antenna was made on RO3003™. Two different antennas were designed, at 60 and 80 GHz respectively. It is demonstrated that the silicon substrate can be successfully integrated into an organic package at mm-wave frequencies by securing it mechanically with the NCF layer. Both designs yielded over 15% bandwidth and greater than 10 dBi gain. Good agreement was found between simulation and measurements.

Coupling efficiency of an alignment-tolerant, single fiber, bi-directional link

This paper presents a combination of two broadband dipole antenna arrays packaged in multilayer organic (MLO) substrates at 57 and 80 GHz. The two arrays are fed via a Tee-junction, in a 45 degree configuration. It is shown that simultaneously integrating antennas at these frequencies is possible. Good performance and isolation was obtained for both antennas, with greater than 10% bandwidth. When simultaneously excited, the 57 GHz design yielded close to 9.3 dBi gain, while the 80 GHz design peaked around 10 dBi. Measured results agreed well with simulations.

Hybrid silicon-organic packaged antenna array at 60 and 80 GHz using a low-cost bonding technique

We demonstrate a fully integrated 2×2 SiGe transmitter array at 316 GHz. A novel method is introduced to phase-lock the high frequency signal sources without any additional circuitry. This method suppresses the other possible oscillatory modes automatically. The power of the locked signal sources are combined in the air by the 2×2 on-chip antenna array which are fed with the locked sources. This array is scalable to larger sizes in the same layout style. This array transmitter utilizes Colpitts oscillators as high frequency signal sources; however, this method can be applied to any other oscillator architecture to perform the frequency and phase locking. The frequency of this transmitter follows the simple equations for a single Colpitts oscillator, thereby facilitating the design of the circuit.

Dual frequency organically packaged antenna arrays at 57 and 80 GHz

This paper presents, for the first time, the integration of V-Band and W-Band antennas with SPDT switch on organic Liquid Crystal Polymer (LCP) substrate. A wideband chip to package wire-bond transition was designed so that the insertion loss is minimized. The antennas were designed and optimized for frequency operation at 57 and 80 GHz with a gain of 10.5 and 9.5 dBi. The gain, S11, E-plane and H-plane Co- and Cross-polarization measurements were conducted and successfully demonstrated a passive antenna gain of 10.08 dBi from 54-61 GHz for V-Band antenna with minimal deviation of 1.2 dB in the gain. Simulation results show gain of around 9.44 dBi from 77-85 GHz for W-band Antenna. Return loss also demonstrates 6 GHz and 8 GHz of 10 dB bandwidth (10% B.W) for V-Band and W-Band antennas respectively.

A 2×2, 316 GHz SiGe scalable transmitter array with novel phase locking method and on-die antennas

This paper presents for the first time, the use of a microfluidic channel with organic substrates to reduce the size of different antenna designs at 915 MHz (dipole and loop). The channel was created by drilling a cavity on a 50 mil RO3003™ substrate and bonding it to two 5 mil substrates in order to seal the structure. Compared to designs fabricated on an unperturbed substrate, the overall size reduction in length for the dipole with water-filled channel was ~44% (60 mm), while a 54% reduction in area was observed for its loop counterpart. Broad bandwidths of 22% and 11% were achieved for the water loaded dipole and loop, respectively. The results obtained for both designs agreed well with simulations.