A bi-directional quasi-optical lens amplifier

In this paper, a -band power amplifier based on a resonant slotted-waveguide-to-microstrip power-dividing/combining circuit is presented. The advantages of this structure are its low profile, ease of fabrication, as well as its potential for high power-combining efficiency. In addition, efficient heat sinking of monolithic microwave integrated circuit (MMIC) devices is achieved. A slotted-waveguide power amplifier using eight MMIC amplifiers was designed and fabricated. The measured power-combining efficiency at 33 GHz is 72%. In addition, simulation results predicting the performance degradation of the slotted-waveguide power amplifier due to multiple device failure are presented. Index Terms--band, power amplifier, power combining, slotted waveguide.

Section: Simulation and Experimental Resultssupporting

confidence: 55%

“…Several techniques, such as quasi-optical and waveguide-based spatial power-combining approaches, have been proposed to address this issue [2]- [6]. At -band, the waveguide-based 1 2 and 2 2 power-amplifier modules were reported in [6] with a power-combining efficiency of 83%.…”

Section: Introductionmentioning

confidence: 99%

A Ka-band power amplifier based on a low-profile slotted-waveguide power-combining/dividing circuit

Jiang

Liu

Ortiz

et al. 2003

“…In the current case, where the dielectric structure is confined between two metallic sheets, the guided modes are those of the resulting parallel plate waveguide. The frequency of the lowest order resonance can be calculated from (4) where is the speed of light, is the periodicity, is the relative permittivity of the substrate, and is the incidence angle. The lowest order mode can be excited by an incident wave scanned in either -or -planes.…”

Section: A Floquet-mode Analysismentioning

confidence: 99%

Study of 2-bit Antenna–Filter–Antenna Elements for Reconfigurable Millimeter-Wave Lens Arrays

Cheng

Abbaspour-Tamijani

2006

This paper presents a new reconfigurable antenna-filter-antenna (AFA) element based on slot antennas and switchable resonators. This reconfigurable AFA can operate in four modes of operation as a three-or four-pole filter, and yields a 2-bit variable phase delay. As a result, the multimode AFA can be used as the building block of 2-bit adaptive lens arrays. This paper details design, modeling, and miniaturization of the reconfigurable AFA, and demonstrates its performance through preconfigured prototypes. The proposed AFA has a loss of 1.4-1.6 dB measured at 32 GHz in both three-and four-pole filter modes, and exhibits a frequency response that is almost insensitive to the angle of incidence. Several proof-of-concept fixed lens arrays have been also fabricated for output beams scanned to 0 , 15 , 30 , 45 , and 60 in the -and -plane. The measurement results show that the output beam can be scanned to 60 in both principle planes, with a worst case sidelobe level of less than 11 dB and a scan loss that hardly exceeds the theoretical limit.Index Terms-Antenna-filter-antennas, beam steering, frequency-selective surface (FSS), microelectromechanical systems (MEMS) antennas, phase shifters, reconfigurable antennas.

“…By providing high gain, narrow beamwidth and low sidelobes in different directions, the RF lens has been fully utilized in applications such as radars and satellite communication systems [27]. Traditional design of lens antenna has consisted of an array of antennas used with variable-length transmission lines to create the aperture phase profile [28]- [30]. Another promising antenna design that uses RF lenses with an antenna array in a MIMO system was considered in [1], [31]- [34].…”

Section: Introductionmentioning

confidence: 99%

RF Lens-Embedded Massive MIMO Systems: Fabrication Issues and Codebook Design

Kwon

Lim

Min

et al. 2016

Abstract-In this paper, we investigate a radio frequency (RF) lens-embedded massive multiple-input multiple-output (MIMO) system and evaluate the system performance of limited feedback by utilizing a technique for generating a suitable codebook for the system. We fabricate an RF lens that operates on a 77 GHz (mmWave) band. Experimental results show a proper value of amplitude gain and an appropriate focusing property. In addition, using a simple numerical technique-beam propagation method (BPM)-we estimate the power profile of the RF lens and verify its accordance with experimental results. We also design a codebook-multi-variance codebook quantization (MVCQ)-for limited feedback by considering the characteristics of the RF lens antenna for massive MIMO systems. Numerical results confirm that the proposed system shows significant performance enhancement over a conventional massive MIMO system without an RF lens.Index Terms-Massive MIMO, RF lens antenna, beam propagation method, limited channel feedback, multi-variance codebook quantization method.