Jim Wight

ABSTRACT This paper presents a Two Layer Artificial Neural Network (2LANN) model for linearization of pico-cell power amplifiers which output approximately 2W or less. Towards the goal of realizing efficient real-time pre-distortion hardware, optimization of the 2LANN model is done based on hardware considerations. The parameters of our proposed 2LANN model are obtained by measuring the wideband inputs and outputs of a Device Under Test (DUT). The said inputs and outputs are then used to train the 2LANN to exhibit system inversion of the DUT. The trained 2LANN is verified by observing its ability to linearize a 2W Class AB power amplifier with a 4-carrier WCDMA signal as its stimulus. The performance metrics for linearity are the dynamic AM-AM and AM-PM characteristics, Adjacent Channel Power Ratio (ACPR), and Error Vector Magnitude (EVM). The measured ACPR improvements due to the proposed pre-distorter are 15dB and 12dB at frequency offsets of 5MHz and 10MHz respectively. The linearized power amplifier also yields a measured EVM improvement of 2%. A comparison of our proposed model with previously published pre-distortion schemes shows the excellent linearization capability of our 2LANN.

This paper proposes a continuous waveform to realize low transmitted power in a Radar system. The proposed waveform utilizes a pulsed compression scheme based on phase-coded modulation and linear FM which combines the desirable properties of both types of modulation. This paper also verifies waveform operation under channel effects such as multipath and noise. We determine power optimization due to

We have created a new architecture for the detection and location of specific buried targets. The system uses a combination of acoustic vibrations and electromagnetic waves to achieve highly specific target recognition, and a multistatic configuration to determine target location. The mechanical vibration resonance properties of the constituent elements of the targets constitute a signature which can be identified in

This paper describes the design and behavior of a 12-GHz push-push dielectric resonator oscillator in a phase-locked environment. This phase-locked dielectric resonator oscillator (PLDRO) differs from conventional designs on many fronts. First, it uses a push-push oscillator for its improved phase noise and reduced fundamental frequency. Second, the phase detection is implemented at a 3-GHz IF as an alternative to

ABSTRACT form only given, as follows. This paper proposes a new approach for realizing a compact SPDT switch incorporating compact, elevated coplanar waveguide (ECPW) series stubs in conjunction with CPS series stubs in order to extend the operating frequency. The design technique has been successfully demonstrated using a multi-layer 90nm CMOS process. The proposed SPDT switch takes advantage of the multi-level metallization processes offered in CMOS technology. The intrinsic area of the fabricated 3D SPDT switch is reduced.

The air-gap three-dimensional symmetric inductor is developed by using an MMIC air bridge approach to realize a suspended inductor. The proposed inductor has a very high quality factor achieving a Q factor of about 30 for a 2.4 nH air-gap symmetric inductor. This paper also presents a miniature semi-lumped low-pass filter composed of a cascade of the proposed elevated low-loss lumped inductors and ultra-low impedance air gap thin film microstrip line (TFMS) sections. This results in a wide stopband up to a high frequency and, when combined with high quality factor suspended inductors, also gives a sharp roll-off at the cutoff frequency. The combined characteristics of these elements make for excellent low-pass filter performance. Finally, compact and harmonic suppression semi-lumped stubs based on a CPW/thin film microstrip combination using 3D on-chip air-core elevated symmetric inductors are proposed.

An analytical method is presented for determining the probability of bit error for fast frequency-hopped M-ary noncoherent frequency-shift-keyed (NCFSK) communication systems with time diversity and linear diversity combining. The method is suitable for obtaining performance both in partial-band noise jamming plus system noise and in multiple-tone jamming plus system noise. The analysis of 8-ary and binary NCFSK with a constant

The authors demonstrate an analysis method for finding the probability of detection of a synchronization probe burst when time diversity is employed. They introduce an analytical approach that is capable of determining the performance of a number of diversity combining algorithms. The analysis uses circularly symmetric function theory, Fourier-Bessel series, and Fourier series. Examples show the calculation of probability of

Increasing the read distance of a Radio Frequency Identification (RFID) system is a challenging problem. A new Ultra High Frequency (UHF) RFID reader antenna has been designed to increase the coverage area. A Quadrifilar Helix Antenna (QFHA) with a shaped radiation pattern has been simulated to verify its performance. The shaped radiation pattern of the QFHA will increase read distance when the reader antenna is centered above a coverage area.

In this work, we propose the use of elevated center coplanar waveguide (EC-CPW) transmission lines in CMOS technology to alleviate the technology limitations of achieving extreme impedances with conventional CPW lines, particularly, high impedances. High impedance lines are required to facilitate the design of matching networks and to reduce the size of the passive components by utilizing capacitively loaded high-impedance lines. This paper presents the measured and simulated performance of these lines and their implementation in building a 60 GHz reduced-size 90° coupler. The coupler's size is 0.102 mm2 and it is well suited for use in the design of radio front-ends of 60 GHz high data-rate wireless systems.

On-chip transmission lines in silicon technologies suffer from the low-resistivity substrate and geometric limitations imposed by layout and metal density design rules. In this paper, we demonstrate that 3D coplanar strip (3DCPS) transmission lines can be utilized to overcome both problems by taking advantage of the multiple metal layers available. A test chip was designed to validate the concept. The paper also presents a family of novel 3D series/shunt matching stub structures based on the 3DCPS and ECPW/TFMS combination. Experimental results are presented in support of the proposed structures.

We investigate the limits of frequency resolution attainable in a nonlinear waveguide optical spectrometer, including the effects that are due to surface distortions and waveguide inhomogeneities, and demonstrate that the frequency-resolving capability is directly scalable with the radiating aperture length. The resolution of the waveguide is diffraction limited, and therefore the far-field radiation pattern can be used to characterize the phase variations along the waveguide that are due to surface distortions. The use of this device as a highly sensitive deformation sensor is demonstrated by application of a distortion to the waveguide and confirmation of the far-field diffraction pattern generated.