Electronically steerable passive array radiator antennas for low-cost analog adaptive beamforming

Ohira, Takashi; Gyoda, Koichi

doi:10.1109/past.2000.858918

Cited by 153 publications

(97 citation statements)

References 3 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…Example 2: A general consensus in the field of antenna design is that a satisfactory beamforming making nulls at an arbitrary number of directions is possible only when a sufficient number of (antenna) active elements are exploited in such a way that the size of the antenna array becomes several multiples of the wavelength. Many works in the past decade, e.g., [28] and [29], have concentrated on designing passive array antennas that are capable of making a null only at one direction. For instance, the study in [29] presents such a design based on a genetic algorithm whose running time is reported to be more than four weeks.…”

Section: Simulation Resultsmentioning

confidence: 99%

Solving Large-Scale Hybrid Circuit-Antenna Problems

Lavaei

Babakhani

Hajimiri

et al. 2011

IEEE Trans. Circuits Syst. I

View full text Add to dashboard Cite

Abstract-Motivated by different applications in circuits, electromagnetics, and optics, this paper is concerned with the synthesis of a particular type of linear circuit, where the circuit is associated with a control unit. The objective is to design a controller for this control unit such that certain specifications on the parameters of the circuit are satisfied. It is shown that designing a control unit in the form of a switching network is an NP-complete problem that can be formulated as a rank-minimization problem. It is then proven that the underlying design problem can be cast as a semidefinite optimization if a passive network is designed instead of a switching network. Since the implementation of a passive network may need too many components, the design of a decoupled (sparse) passive network is subsequently studied. This paper introduces a tradeoff between design simplicity and implementation complexity for an important class of linear circuits. The superiority of the developed techniques is demonstrated by different simulations. In particular, for the first time in the literature, a wavelength-size passive antenna is designed, which has an excellent beamforming capability and which can concurrently make a null in at least eight directions.

show abstract

Section: Simulation Resultsmentioning

confidence: 99%

Solving Large-Scale Hybrid Circuit-Antenna Problems

Lavaei

Babakhani

Hajimiri

et al. 2011

IEEE Trans. Circuits Syst. I

View full text Add to dashboard Cite

show abstract

“…Hence, switched beam antennas seems to be a feasible option as a first generation technology to be used in ad hoc networks. Indeed, efforts aiming to enhance mobile devices with directional antennas already exist, an example is the ESPAR (Electronically Steerable Passive Array Radiator) antenna currently being developed at ATR (ACR) [15]. In this work we assume that each mobile terminal is equipped with a switched beam antenna, such as ESPAR, and to have similar characteristics as those assumed in [1], [3], [14].…”

Section: Antenna Modelmentioning

confidence: 99%

Deafness Resilient MAC Protocol for Directional Communications

Bordim¹,

Nakano

2010

IEICE Trans. Inf. & Syst.

View full text Add to dashboard Cite

SUMMARYIt is known that wireless ad hoc networks employing omnidirectional communications suffer from poor network throughput due to inefficient spatial reuse. Although the use of directional communications is expected to provide significant improvements in this regard, the lack of efficient mechanisms to deal with deafness and hidden terminal problems makes it difficult to fully explore its benefits. The main contribution of this work is to propose a Medium Access Control (MAC) scheme which aims to lessen the effects of deafness and hidden terminal problems in directional communications without precluding spatial reuse. The simulation results have shown that the proposed directional MAC provides significant throughput improvement over both the IEEE802.11DCF MAC protocol and other prominent directional MAC protocols in both linear and grid topologies.

show abstract

“…The antenna interfaces with a single channel microwave self-balancing modulation radiometer are able to tune in more than one frequency [4][5][6]. Different wavelengths of the tunable frequency shall penetrate into different depths inside the human tissue, hence providing a series of temperature measurements in succeeding depths [7,8].…”

Section: Introductionmentioning

confidence: 99%

A Novel Antenna System for Body Temperature Change Detection Appropriate for Multi-Channel Microwave Radiometry

Nikolopoulos¹,

Capsalis²

2013

PIER M

View full text Add to dashboard Cite

Abstract-A planar inverted F antenna is combined with passive (reactively loaded) elements in order to implement a multi-frequency configuration appropriate for biomedical applications in microwave frequencies. A case study of an electronically Reconfigurable PIFA (R-PIFA) is pursued for the detection of temperature abnormalities in human tissue phantom using microwave radiometry, where the performance of the structure is optimized with respect to input impedance matching in multiple frequencies. The optimization of the array is performed using a Genetic Algorithm (GA) tool as a method of choice. Due to its limited physical size, the proposed R-PIFA can also be used as a portable antenna system for deployment in mobile medical applications.

show abstract

Electronically steerable passive array radiator antennas for low-cost analog adaptive beamforming

Cited by 153 publications

References 3 publications

Solving Large-Scale Hybrid Circuit-Antenna Problems

Solving Large-Scale Hybrid Circuit-Antenna Problems

Deafness Resilient MAC Protocol for Directional Communications

A Novel Antenna System for Body Temperature Change Detection Appropriate for Multi-Channel Microwave Radiometry

Contact Info

Product

Resources

About