The paper proposes a system consisting of novel programmable system on chip (PSoC)-controlled phase shifters which in turn guides the beam of an antenna array attached to it. Four antennae forming an array receive individual inputs from the programmable phase shifters (IC 2484). The input to the PSoC-based phase shifter is provided from an optimized 1:4 Wilkinson power divider. The antenna consists of an inverted L-shaped dipole on the front and two mirrored inverted L-shaped dipoles mounted on a rectangular conductive structure on the back which resonates in the ISM/Wi-Fi band (2.40–2.48 GHz). The power divider is designed to provide the feed to the phase shifter using a beamforming network while ensuring good isolation among the ports. The power divider has measured S11, S21, S31, S41, and S51 to be −14, −6.25, −6.31, −6.28, and −6.31 dB, respectively at a frequency of 2.45 GHz. The ingenious controller is designed in-house using a PSoC microcontroller to regulate the control voltage of individual phase shifter IC and generate progressive phase shifts. To validate the calibration of the in-house designed control circuit, the phased array is simulated using $s_p^2$ touchstone file of IC 2484. This designed control circuit exhibits low insertion loss close to −8.5 dB, voltage standing wave ratio of 1.58:1, and reflection coefficient (S11) is −14.36 dB at 2.45 GHz. Low insertion loss variations confirm that the phased-array antenna gives equal amplitude and phase. The beamforming radiation patterns for different scan angles (30, 60, and 90°) for experimental and simulated phased-array antenna are matched accurately showing the accuracy of the control circuit designed. The average experimental and simulated gain is 13.03 and 13.48 dBi respectively. The in-house designed controller overcomes the primary limitations associated with the present electromechanical phased array such as cost weight, size, power consumption, and complexity in design which limits the use of a phased array to military applications only. The current study with novel design and enhanced performance makes the system worthy of the practical use of phased-array antennas for common society at large.

A novel idea for generating directional electromagnetic beam using a metamaterial absorber for enhancing radiation from a microwave antenna in the S-band is presented herewith. The metamaterial structure constitutes the well-known stacked dogbone doublet working in the absorption mode. The reflection property of the dogbone metamaterial absorber, for the non-propagating reactive near-field, is utilized for achieving highly enhanced and directional radiation characteristics. The metamaterial absorber converts the high-spatial reactive spectrum in the near-field into propagating low-spatial spectrum resulting in enhanced radiation efficiency and gain. The gain of a printed standard half-wave dipole is enhanced to 10 dBi from 2.3 dBi with highly directional radiation characteristics at resonance.

Wideband dipole antennas are proposed using the multi-mode resonance concept. By symmetrically introducing one-pair or two-pair of stubs at the nulls of current distribution of the second odd-order mode, two radiation modes are excited in a single, center-fed dipole resonator. Using these stubs, the second odd-order mode gradually moves down to its first counterpart, resulting to achieve a wideband radiation with two resonances. Prototype antennas are then fabricated to experimentally validate the design approach. Compared with a reference dipole with a bandwidth of 17%, the proposed dipole's bandwidth can be effectively increased to 49.7%.

A new ultra-high frequency radio frequency identification (RFID) tag antenna, which is comprised a U-shaped tuning stub and a dipole radiator for different permittivity surfaces is investigated, fabricated, and measured. For a conjugate match to the NXP G2XM chip impedance of 29–j137 at 915 MHz, a dipole tag antenna with U-shaped stubconnected to dipole arms was designed. Simple size adjustments of the U-shaped tuning stub and dipole radiator of the antenna allow for easy control of the antenna resistance and inductive reactance, from which the chip impedance requirement may be readily satisfied. The read range of the prototype antenna attached on a different permittivity surfaces (εr = 1–4) can reach more than 4.5 m, which has been tested for an RFID reader with 4.0 W of effective isotropic radiated power. The antenna structure consists of two dipole load bars and two loop electrically connected. The design offers more choice of freedom to tune the input impedance of the proposed antenna. Measurement data are presented which are in good agreement with simulation results. The design is suitable for mounting on all kinds of objects. The fabricated tag sensitivity of −3 dBm, read range of 7 m on the x–z and y–z planes, and the measured orientation radiation patterns were obtained in the desired frequency band.