Impedance matching for curl and truncated spiral antennas above the ground plane

Impedance Matching for RFID Tag Antennas

Passive UHF RFID tag consists of a microchip attached to an antenna. Proper impedance match between the antenna and the chip is crucial in RFID tag design. It directly influences RFID tag performance characteristics such as the read range. It is known that an RFID microchip is a nonlinear load whose complex impedance varies with the frequency and the input power. We investigate the effect of us...

The Radiation Quality Factor Of Vertically Polarized Spherical Antennas Above A Conducting Ground Plane

Impedance matching and tuning of non-resonant mobile terminal antennas

Aalto University, P.O. Box 11000, FI-00076 Aalto www.aalto.fi Author Risto Valkonen Name of the doctoral dissertation Impedance matching and tuning of non-resonant mobile terminal antennas Publisher School of Electrical Engineering Unit Department of Radio Science and Engineering Series Aalto University publication series DOCTORAL DISSERTATIONS 40/2013 Field of research Radio Engineering Manusc...

Optimization of Impedance Plane Reducing Coupling between Antennas

This paper provides a solution for the design optimization of two-dimensional impedance structures for a given electromagnetic field distribution. These structures must provide electromagnetic compatibility between antennas located on a plane. The optimization problem is solved for a given attenuation of the complete field. Since the design optimization gives a complex law of impedance distribu...

A Monofilar Spiral Antenna and Its Array Above a Ground Plane—Formation of a Circularly Polarized Tilted Fan Beam

A monofilar spiral antenna is analyzed in the presence of a conducting plane reflector, using the method of moments. The circumference of the spiral antenna is chosen to be 2.3 wavelengths. A tilted beam of circular polarization is realized by superposing the fields from two active regions. The gain of the tilted beam is approximately 8 dB. The frequency bandwidths for 1-dB gain drop and 3-dB a...