Engineering and Technology Journal

A new compact single feed square ring patch antenna using meandered 4λ transformer is designed, for frequency and polarization diversity. The proposed antenna is constructed from a square ring patch antenna, and two orthogonal meandered cascaded 4λ transformer (OMCT), incorporated with six switches for frequency and polarization reconfiguration purposes. The OMCT with switches is necessary to get good impedance bandwidth (BW) and axial ratio bandwidth (ARBW) for circular polarization state. In addition, it utilized to excite the antenna at two orthogonal locations, with equal magnitude and quadratic in phase, for achieving circular polarization mode at resonant frequencies 2.44GHz, 4.7GHz, and 5.6GHz. Moreover, it can excite the antenna as non-orthogonal modes for various other frequency bands, such as 2.89 GHz, 3.49 GHz, 4.9 GHz, 5.2GHz, 5.49GHz, 6.16GHz and 3.1GHz as linear polarization (LP) state. The proposed antenna has a compact low profile planar structure with area equal to 23mm2. Simulation and measured results show that the proposed antenna demonstrates a reasonable impedance bandwidth, and axial ratio in the circularly polarized state. Simulation results have been obtained from commercial CST-2014 Microwave Studio. The proposed antenna is fabricated for simulation result verification, and the implemented antenna is tested using R&S ZVL13 Vector Network Analyzer. The experimental confirms the simulation results.

A low profile compact microstrip antenna for GPS (L1/L2) application has been
presented in this paper. The proposed antenna design is based on the 3rd iteration
Minkowski-like pre-fractal geometry. The resulting antenna design offers a compact size,
low profile and light weight making it suitable for use in handheld applications. Antenna
performance has been evaluated using the EMSightTM from the Applied Wave Research.
The proposed antenna has shown to possess two resonance bands (for return loss .-10
dB) covering the two GPS bands. Reasonable radiation characteristics have been achieved
at the GPS frequencies (L1:1575.42 } 10.23 MHz, L2:1227.60 } 10.23 MHz) with good
circular polarization characteristics. Realized circular polarization Bandwidths (for axial
ratio . 3 dB) are found to cover adequately those required for these GPS bands.

A new reduced size single probe fed microstrip patch antenna with irregular slits
has been presented to be used as a receiving antenna for Global Positioning Systems
(GPS) integrated with cellular handheld mobile wireless systems. The proposed design is
based on the nearly square microstrip patch antenna with two pairs of orthogonal slits
cut from the edge. It has been found that this antenna offers further reduction in size
with good radiation properties required for GPS system. The resulting circular
polarization bandwidth (with axial ratio ≤ 3 dB) has been found to meet that required for
this application. The proposed antenna possesses an average gain of 4.5 dB overall the
GPS L1 operation.