University of California

Yuanxun Ethan Wang

Gregory Paul Carman

Robert N Candler

Scott Macklin Keller

Jin-Seong Jeong

Xiating Zou

Kevin Luong

Lap Kun Yeung

A very low frequency (VLF) magnetic field sensor, using spins sourced from insulating ferrimagnetic materials or ferrites, which can achieve high sensitivities competitive with modern sensors while simultaneously maintaining a small size, low power consumption, simplicity of design, and low cost. The magnetic field sensor utilizes nonlinear resonant precession modulation (RPM) dynamics of subatomic spins to attain parametric amplification of a magnetic field.

Detecting very low frequency magnetic fields based on precession modulation of magnetic field sensors

Parametric flat lenses, which are an alternative to conventional flat lenses, are described for performing near-field imaging and electronic beam scanning. These lenses can electronically direct the near or far fields, and in some cases even achieve a conversion gain. The lens incorporates a plurality of input and output antennas between which are a plurality of parametric mixers. The parametric mixers can be utilized as well to change phase relationships in accommodating different input pattern or directing the output in different ways. The disclosure also describes a proof of concept implementation using off the shelf components.

Parametric flat lenses for near-field imaging and electronic beam scanning

Sequentially-Switched Delay Line (SSDL) can realize passive, nonmagnetic and non-reciprocal components for electromagnetic waves over ultra-wideband through the breaking of the time-reversal symmetry. A SSDL structure with six sections of transmission lines and five Single Pole Double Throw (SPDT) switches has been proposed as a three-port circulator in the literature. In this disclosure, a simpler structure consisting of only two sections of transmission lines with two switches is proposed, which can operate as a two-port non-reciprocal phase shifter (gyrator) with two SPDT switches, a three-port circulator with one DPDT switch and one SPDT switch, or a four-port circulator with two DPDT switches. Simulation results for one design at radio frequency demonstrated the expected non-reciprocal behavior from DC to 1.5 GHz for aforementioned three configurations.

Two-port, three-port and four-port non-reciprocal devices with sequentially switched delay lines (SSDL)

An apparatus and method for enhancing full-duplex radio communications using an indented transmitter and receiver antenna. A multi-element antenna array is configured with each antenna coupled to a circulator that has connections to both a transmission path and a receiving path. The apparatus is configured with indentations that provide a tilting of the array from its broadside to create a progressive phase delay between adjacent pairs of elements. Transmitted and received waves travel a single trip through the indention, while antenna reflection or circulator leakage travels a round trip through indention, so that these signal components can be readily separated to achieve high levels of isolation during full-duplex transmitting and receiving.

Indented antenna array for transmitter to receiver isolation

An antenna apparatus utilizing bulk acoustic wave (BAW) resonances to transfer dynamic strain across multiple layers, which include piezoelectric layers coupled to magnetostrictive material layers. In at least one embodiment, a piezoelectric layer is coupled to a magnetostrictive layer to which another layer having similar acoustic properties as the piezoelectric layer is coupled as an inertial buffer. These multiple layers comprise a strain media to provide a vertical multiferroic coupling which couples electric field, magnetic field, and mechanical fields. Electrodes are coupled to excite one of the piezoelectric layers for injecting acoustic waves into the structure from which electromagnetic radiation is generated out of the plane.

Bulk acoustic wave mediated multiferroic antennas

A passive circulator utilizing sequentially-switched delay lines (SSDL) in which delay line sections are sequentially turned on and off to achieve non-reciprocity to provide rejection/separations between different signals at the same/similar frequency, such as between a transmitted and received signal. The circulator is well-suited for on-chip integration and can be utilized across a wide frequency range. Various embodiments are described for separating signal waveforms.

Ultra-wide band circulators with sequentially-switched delay line (SSDL)

A tunable notch filter/amplifier based on the non-reciprocal operation of distributedly modulated capacitors (DMC) formed for an RF front end. In one embodiment within the DMC is formed into a ring resonator with a filter between its ends to allow resonance to build up only at an up-converted frequency, and tune the frequency of the whole received band instead of the resonant frequency of the filter alone. In addition a circulator is described for passing different signals in different directions, but at the same frequency, while maintaining signal separation.

Non-reciprocal, tunable notch amplifying RF front-ends based on distributedly modulated capacitors (DMC)

A band pass filter is implemented utilizing Channelized Active Noise Elimination (CANE) in combining Finite Impulse Response (FIR) filtering into a radio frequency (RF) transmitter, or transmission path. The FIR filtering is performed in a combination of multiple conversion paths of delay units, vector modulators and PAs so that the low pass characteristics of the FIR filter are upconverted on the adjacent frequency of the carrier to form a band pass filter at the output of the transmitter. Use of CANE avoids the need of high sampling rates, while also eliminating the need of either broad bandwidth delay lines or modulated power amplifiers. The technique is well-suited for suppression of the quantization noise generated in RF transmitters with bitstream modulations such as the Envelope Delta Sigma Modulation (EDSM).

Channelized active noise elimination (CANE) for bit stream RF transmitters

A non-reciprocal radio frequency transceiver front end utilizing multiple time-varying transmission lines (TVTLs) implemented using distributed modulated capacitors (DMC) to exploit time-varying properties of transmission line structures to isolate the transmit and receive signals. The TVTLs are coupled at an input side to an antenna and ground through a first 90 degree coupler, and the outputs of the TVTLs are coupled through a second 90 degree coupler for connection to a receiver and transmit circuit, respectively. The apparatus allows simultaneously operating a transmitter and receiver sharing a single antenna (or single antenna array).

Non-reciprocal components with balanced distributedly modulated capacitors (DMC)

An apparatus and method for realizing non-reciprocal components, such as isolators and circulators, for operation over a broad bandwidth without requiring magnetic components/material which would prevent integrated circuit manufacture utilizing standard processes is presented. In one example, a circulator is described including varactor diodes coupled at each unit cell in a balanced manner between halves of a differential signal path and halves of a differential carrier path. In another example, variable capacitors are coupled at each unit cell between a signal path and ground, and having a tuning input of the variable capacitor receiving a signal from a carrier path.

Distributedly modulated capacitors for non-reciprocal components

Improved power amplifiers and related methods using a pulsed load modulation technique that controls the load modulation characteristics in a digital pulsed fashion.

Growing community of inventors

Manhattan Beach, CA, United States of America

Yuanxun Ethan Wang