Timothy P. McKenna

Experimental Demonstration of Photonic Millimeter-Wave System for High Capacity Point-to-Point Wireless Communications

We present experimental results of 10 Gb/s wireless communications over a distance of 520 meters in the W-band. The transmitter makes use of photonic upconversion with a high bandwidth photodiode to allow for minimum hardware at the antenna. We present results with two receiver configurations. The first uses all electronic methods with a balanced Schottky diode mixer for downconversion, and the second uses photonics to limit the hardware at the receive antenna by photonically generating the local oscillator drive signal and transporting the intermediate frequency signal over a microwave photonic link.

Photonic Beamsteering of a Millimeter-Wave Array With 10-Gb/s Data Transmission

We present experimental results of 10-Gb/s W-band wireless transmission using a four element linear array. The 10-Gb/s transmission is shown when photonically steered to 0° and ± 35° from antenna boresight. In this letter, photonic techniques are used for signal generation, distribution, and time delay. Photonic true-time delay is shown to allow for steering of broadband millimeter-wave signals with no noticeable beam squint across frequency. High power, high frequency photodiodes are used for optical-to-electrical conversion to directly radiate from the array without power amplifiers.

Millimeter-Wave Photonics for Communications and Phased Arrays

Abstract This article presents recent developments in millimeter-wave communications architectures featuring broadband photonic signal generation, up-conversion and down-conversion, as well as true-time-delay photonic steering of millimeter-wave arrays. These developments will support future high-capacity millimeter-wave wireless communications by enabling broadband signals to be generated and converted between baseband and millimeter-wave carrier frequencies without electronic heterodyne systems and by permitting the use of true-time-delay beamsteering in millimeter-wave array apertures.

Photonic downconverting link with digital linearization

We experimentally demonstrate a digitally linearized high dynamic range downconverting microwave photonic link. The system is limited in frequency only by the 10 GHz 3-dB bandwidth of the optical modulators used and is demonstrated at 9 GHz. Digital linearization suppresses third order intermodulation distortion by as much as 39 dB. The linearization is shown for a single tone, a two tone, and a 1 MHz bandwidth input signal.

A W-band photonic array

A four-element W-band linear array with photonic true-time delay beam steering is presented. The array demonstrates the necessary technology leading towards an integrated two-dimensional photonically steered array. Because the antenna elements are photonically fed, only the amplifiers and photodiodes need to be local to the aperture, with all other associated hardware remoted. Wideband operation is demonstrated, showing operation from 75-100 GHz, and beam steering from 84-100 GHz.

Recent progress in photonic analog-to-digital converters

Progress in photonic analog-to-digital conversion architectures and system design issues will be discussed taking full advantage of recent photonic, electronic and signal processing technologies. Specifically targeted will be architectures supporting operational frequencies exceeding the sampling rate as well as recent work on compressive sampling, where instantaneous bandwidths larger than the sampling rate are obtainable.

Photonic millimeter wave system for high capacity wireless communications

Pushing the wireless communications capacity above 100 Gbps will require new spectral regions and new technologies and techniques. Millimeter wave photonics technology appears poised to meet the new bandwidth and fidelity challenges and offers novel architectures, techniques, and system capabilities. This paper presents recent work developing and demonstrating millimeter wave photonic carrier generation, upconversion, downconversion and photonic millimeter wave arrays as well as how they fit into a new class of wireless communications architecture.

A multi-channel photonic transceiver

This paper presents a novel photonic transceiver architecture for digital array applications. The architecture utilizes optical remoting for minimal hardware impact at the antenna and phase encoding for improved linearity. The individual elements are addressed through wavelength division multiplexing and photonic downconversion is used to increase the linearity of the photonic receiver. The architecture is evaluated through a 10 GHz, two-element experimental prototype system. The phase stability of the system is evaluated by measuring the relative phase drift between the two elements at the outputs of the transmitter and receiver. The transmitter exhibits low phase error, on the order of 10 millidegrees, while the receiver shows a phase error of approximately 1 degree over a time scale of 2 ms at uncontrolled laboratory temperatures.