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Full-Text Articles in Systems and Communications
Monofilar Spiral Slot Antenna For Dual-Frequency Dual-Sense Circular Polarization, Xiulong Bao, Max Ammann
Monofilar Spiral Slot Antenna For Dual-Frequency Dual-Sense Circular Polarization, Xiulong Bao, Max Ammann
Articles
A dual-band antenna with right-hand circular polarization for the first frequency and the counter polarization at the second frequency is realized with compact printed spiral slots. The coupled spiral slots are fed by a 50 Ω microstrip line. Dual-sense circularly-polarized performance is achieved by realizing oppositely-directed current rotation for the two frequency bands. A parametric study shows that the additional slot significantly improves the bandwidth for both frequency bands. Measured results show that the fractional impedance bandwidth is greater than 18% for both bands. The 3 dB axial-ratio bandwidths are 4.5% and 3.5% for the RHCP and LHCP bands, respectively.
Wideband Dual-Frequency Dual-Polarized Dipole-Like Antenna, Xiulong Bao, Max Ammann
Wideband Dual-Frequency Dual-Polarized Dipole-Like Antenna, Xiulong Bao, Max Ammann
Articles
A wideband dual-frequency dual-polarized printed antenna is proposed for LTE, WLAN, and UWB systems. The dual-band antenna provides wide impedance bandwidths of 74% with respect to the center frequency of 2.725 GHz, and 39% with respect to the center frequency of 7.15 GHz. An open slot in the ground plane between the feed arms provides an orthogonal path to realize an embedded circularly polarized band at 2.35 GHz with an axial-ratio bandwidth of 16%. Dual-band characteristics are achieved by an asymmetrical dipole-like element and the coupling configuration between the T-shaped feed line and the wide ground-plane slot.
Printed Circularly-Polarized Antenna With Ultra-Wide Axial-Ratio Bandwidth, Xiulong Bao, Max Ammann
Printed Circularly-Polarized Antenna With Ultra-Wide Axial-Ratio Bandwidth, Xiulong Bao, Max Ammann
Articles
A circularly polarised printed dipole-like antenna employing asymmetrical arms and an orthogonal slit in the ground plane is presented. It is fed by a stepped microstrip line which connects to the shorter arm. By utilising surface currents on the asymmetrical arms and the orthogonal feedline structure, circular polarisation is realised. Experimental and numerical data are in agreement and the measured results show a fractional impedance bandwidth of 41.3% (1.77–2.69 GHz) and a wide axial-ratio bandwidth of 38.4% (1.81–2.67 GHz).
Transparent Patch Antenna On A-Si Thin Film Glass Solar Module, Maria Roo Ons, S. Shynu, Max Ammann, Sarah Mccormack, Brian Norton
Transparent Patch Antenna On A-Si Thin Film Glass Solar Module, Maria Roo Ons, S. Shynu, Max Ammann, Sarah Mccormack, Brian Norton
Articles
An optically transparent microstrip patch mounted on the surface of a commercially available solar module is proposed. The patch comprises a thin sheet of clear polyester with a conductive coating. The amorphous silicon solar cells in the module are used as both photovoltaic generator and antenna ground plane. The proposed structure provides a peak gain of 3.96 dBi in the 3.4-3.8 GHz range without significantly compromising the light transmission in the module. A comparison between copper and transparent conductors is made in terms of antenna and solar performance. The proposed technique is considerably simpler that previous integration approaches.
In-Silico Hyperthermia Performance Of A Near-Field Patch Antenna At Various Positions On A Human Body Model, Sergio Curto, Terrence See, Patrick Mcevoy, Max Ammann, Zhi Ning Chen
In-Silico Hyperthermia Performance Of A Near-Field Patch Antenna At Various Positions On A Human Body Model, Sergio Curto, Terrence See, Patrick Mcevoy, Max Ammann, Zhi Ning Chen
Articles
A compact patch applicator designed to enhance targeted energy coupling at 434 MHz is a key enabler for sensitizing temperature increments in body regions containing superficial tumours. A detailed FDTD body model is used to explore simulated RF coupling and temperature increments for typical clinical conditions. The antenna impedance matching, specific absorption rate and thermal distribution parameters are evaluated to identify applied performance outcomes. The analysis reveals physiological-RF coupling patterns for an optimised closely-coupled single element applicator.