-A reconfigurable wideband and multiband C-Slot patch antenna with dual-patch elements is proposed and studied. It occupies a compact volume of 50 x 50 x 1.57 (3925mm 3 ), including the ground plane. The antenna can operate in two dual-band modes and a wideband mode from 5 to 7 GHz. Two parallel C-Slots on the patch elements are employed to perturb the surface current paths for excitation of the dual-band and the wideband modes. Two switches, implemented using PIN diodes, are placed on the connecting lines of a simple feed network to the patch elements. Dual-band modes are achieved by switching "ON" either one of the two patch elements, while the wideband mode with an impedance bandwidth of 33.52% is obtained by switching "ON" both patch elements. The frequencies in the dual-band modes can be independently controlled using positions and dimensions of the C-Slots without affecting the wideband mode. The advantage of the proposed antenna is that two dual-band operations and one wideband operation can be achieved using the same dimensions. This overcomes the need for increasing the surface area normally incurred when designing wideband patch antennas. Simulation results are validated experimentally through prototypes. The measured radiation patterns and peak gains show stable responses and are in good agreements. Coupling between the two patch elements plays a major role for achieving the wide bandwidth and the effects of mutual coupling between the patch elements are also studied.

A novel transparent UWB antenna for photovoltaic solar-panel integration and RF energy harvesting is proposed in this paper. Since the approval by the Federal Communications Committee (FCC) in 2002, much research has been undertaken on ultrawide band (UWB) technology especially for wireless communications. However, in the last decade, UWB has also been proposed as a power harvester. In this paper, a transparent cone top tapered slot antenna covering the frequency range from 2.2 GHz to 12.1 GHz is designed and fabricated to provide UWB communications whilst integrated onto to solar panels as well as harvest electromagnetic waves from free space and convert them into electrical energy. The antenna when sandwiched between an a-Si solar panel and glass is able to demonstrate a quasi Omnidirectional pattern that is characteristic of a UWB. The antenna when connected to a 2.55-GHz rectifier is able to produce 18 mV DC in free space and 4.4 mV DC on glass for an input power of 10 dBm at a distance of 5 cm. Although the antenna presented in this paper is a UWB antenna, only an operating range of 2.49 to 2.58 GHz for power scavenging is possible due to the limitation of the narrowband rectifier used for the study.

A breast cancer detection technique using multi-static radar is proposed. For the first time, images are produced using this technique, using backscatter data produced from an anatomically realistic 2D MRI-derived FDTD model of the breast. Successful detection of a 2 mm-diameter tumour is demonstrated, although clarity of detection is dependent on mitigating antenna mutual coupling and skin reflections.Introduction: Breast cancer is one of the most common cancers in women. In 2003, in the US alone, it is estimated that a woman will be diagnosed with breast cancer every three minutes [1]. X-ray mammography is currently the most effective detection technique [2], however it suffers from relatively high missed-and false-detection rates and involves uncomfortable compression of the breast. X-rays are also ionising and this poses limitations on the frequency of screening.Microwave detection of breast tumours is a non-ionising, potentially low-cost modality that relies on the dielectric contrast between healthy and malignant breast tissues [3,4]. The work presented in this Letter falls under the class of ultra-wideband microwave radar techniques, which take advantage of the relatively large microwave scattering crosssections of malignant tumours [5]. Previous theoretical investigations of such techniques have focused on monostatic system configurations [5][6][7][8]. This contribution presents results from a hitherto unexplored variant, based on a multi-static radar technique originally developed for use in landmine detection [9].

A patch antenna is presented which has been designed to radiate into human breast tissue. The antenna is shown by means of simulation and practical measurement to possess a wide input bandwidth, stable radiation patterns and a good front-to-back ratio. Consideration is also given to its ability to radiate a pulse, and in this respect it is also found to be suitable for the proposed application.

Abstract-The design of a small ultra-thin Printed Inverted-F Antenna (PIFA) with independent control on the resonant frequency bands is proposed. The antenna consists of a slotted radiator supported by shorting walls and a small ground plane. The structure is designed and optimized to operate at 2.09, 3.74 and 5 GHz with achievable bandwidths of 11%, 8.84% and 10%, respectively. These three bands cover the existing wireless communication frequency bands from 1.5 -6.8 GHz. Each of the three bands can be controlled independently without affecting the other two bands. The 2.09 GHz band can be controlled to operate between 1.5 -2.09 GHz (33.33%), the 3.74 GHz band can be controlled over the range of 3.57 -4.18GHz (15.76%) and the 5 GHz band can be controlled to cover the band from 5.00 -6.80 GHz (30.50%). Results of intensive investigations using computer simulations and measurements show that the ground plane and the feed locations of the antenna have marginal effects on the performance of the antenna. The effects of the user's hand and mobile phone housing on the return loss, radiation patterns, gains and efficiency are characterized. The measured peak gains of the prototype antenna at 2.09, 3.74 and 5GHz are 2.05, 2.32 and 3.47 dBi, respectively. The measured radiation efficiencies for the corresponding three bands are 70.12, 60.29 and 66.24 % respectively.