40 GHz Monolithic Grid Amplifier

A 36-element monolithic grid amplifier has been fabricated. The peak gain is 4 dB at 40 GHz with a 3-dB bandwidth of 800 MHz. We discuss the design and measurements for the monolithic grid amplifier. The grid includes base stabilizing capacitors which result in a highly stable grid. This is the first report of a successful monolithic grid amplifier

Gain and Stability Models for HBT Grid Amplifiers

A 16-element heterojunction bipolar transistor (HBT) grid amplifier has been fabricated with a peak gain of 11 dB at 9.9 GHz with a 3-dB bandwidth of 350 MHz. We report a gain analysis model for the grid and give a comparison of the measurement and theory. The measured patterns show the evidence of a common-mode oscillation. A stability model for the common-mode oscillation is developed. Based on the stability model, a lumped capacitor gives suitable phase shift of the circular function, thus stabilizing the grid. A second 18-element grid was fabricated, using this theory, with improved stability

A 6.5 GHz-11.5 GHz source using a grid amplifier with a twist reflector

The authors have constructed and tested an oscillator using a grid amplifier with external feedback from a twist reflector. The twist reflector serves two functions; it changes the output polarization to match the input, and its position sets the feedback phase. This permits a wider tuning range than has been possible with previous grid oscillators. The source could be continuously tuned from 8.2 GHz to 11.0 GHz by moving the twist reflector. By moving the polarizer and mirror in the twist reflector independently, a 1.8-to-1 frequency range from 6.5 GHz to 11.5 GHz was achieved. The peak effective radiated power was 6.3 W at 9.9 GHz

A 100-element HBT grid amplifier

A 100-element 10-GHz grid amplifier has been developed. The active devices in the grid are chips with heterojunction-bipolar-transistor (HBT) differential pairs. The metal grid pattern was empirically designed to provide effective coupling between the HBTs and free space. Two independent measurements, one with focusing lenses and the other without, were used to characterize the grid. In each case, the peak gain was 10 dB at 10 GHz with a 3-dB bandwidth of 1 GHz. The input and output return losses were better than 15 dB at 10 GHz. The maximum output power was 450 mW, and the minimum noise figure was 7 dB. By varying the bias, a signal could be amplitude modulated with a modulation index as large as 0.65. Tests show that the grid was quite tolerant of failures-the output power dropped by only 1 dB when 10% of the inputs were detuned. The grid amplifier is a multimode device that amplifies beams of different shapes and angles. Beams with incidence angles up to 30° were amplified with less than a 3-dB drop in gain

Monolithic 40-GHz 670-m W HBT Grid Amplifier

A 36-element monolithic grid amplifier has been fabricated. The active elements are pairs of heterojunction-bipolar-transistors. Measurements show a peak gain of 5 dB at 40 GHz with a 3-dB bandwidth of 1.8 GHz (4.5%). Here we also report comparisons of patterns and tuning curves between the measurements and theory. The grid includes base stabilizing capacitors which result in a highly stable grid. The maximum saturated output power is 670 mW at 40 GHz with a peak power-added efficiency of 4%. This is the first report of power measurements on the monolithic quasi-optical amplifier

Performance and applications of a 100-element HBT grid amplifier

A 100-element 10-GHz grid amplifier has been developed. The active devices in the grid are chips with heterojunction bipolar transistor (HBT) differential pairs that include a resistive network to provide self-bias to the base. The planar metal grid structure was empirically designed to provide effective coupling between the HBTs and free space. The peak gain of the grid was 10 dB at 10 GHz with a 3 dB bandwidth of 1 GHz. The input and output matches are better than 15 dB at 10 GHz. The maximum output power is 450 mW, and the minimum noise figure is 7 dB. Tests show that the grid is quite tolerant of failures-the output power dropped by only 1 dB when the 10% of the inputs were detuned. The device amplifies beams with incidence angles up to 30° with less than a 3-dB drop in power. By providing external feedback with a twist reflector, the grid amplifier can be used as a broadband tunable source. This source could be tuned from 6.5 GHz to 11.5 GHz with a peak effective radiated power (ERP) of 6.3 W at 9.9 GHz

Performance of a 100-element HBT grid amplifier

A 100-element 10-GHz grid amplifier has been devek oped. The active devices in the grid are chips with heterojunction bipolar transistor (HBT) differential pairs. The peak gain of the grid was 10 dB at 10 GHz with a 3-dB bandwidth of 1 GHz. The input and output matches are better than 15 dB at 10 GHz. The maxi- mum output power is 450 roW, and the minimum noise figure is 7 dB. Tests show that the grid is quite tolerant of failures--the output power dropped by only ldB when 10% of the inputs were detuned. The de- vice amplifies beams with incidence angles up to 300 wlth less than a 3-dB drop in power. By providing external feedback with a twist reflector, the grid amplifier can be used as a 6.5-(3Hz to 11.5-GHz tunable source with a peak effective radlated power (EiP) of 6.3 W at 9.9 (3Hz

A Compressed Sensing Parameter Extraction Platform for Radar Pulse Signal Acquisition

In this paper we present a complete (hardware/ software) sub-Nyquist rate (× 13) wideband signal acquisition chain capable of acquiring radar pulse parameters in an instantaneous bandwidth spanning 100 MHz-2.5 GHz with the equivalent of 8 effective number of bits (ENOB) digitizing performance. The approach is based on the alternative sensing-paradigm of compressed sensing (CS). The hardware platform features a fully-integrated CS receiver architecture named the random-modulation preintegrator (RMPI) fabricated in Northrop Grumman's 450 nm InP HBT bipolar technology. The software back-end consists of a novel CS parameter recovery algorithm which extracts information about the signal without performing full time-domain signal reconstruction. This approach significantly reduces the computational overhead involved in retrieving desired information which demonstrates an avenue toward employing CS techniques in power-constrained real-time applications. The developed techniques are validated on CS samples physically measured by the fabricated RMPI and measurement results are presented. The parameter estimation algorithms are described in detail and a complete description of the physical hardware is given