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ABSTRACT: In this article, a new low-cost active antenna for WLAN sensor applications is presented. The proposed system operates as a transceiver whereby the received coded data signal from the broadside direction is retransmitted over a wide area in other directions. This is performed so that a null response at the main pointing angle is maintained. It is formed by a three elements series array connected to high- performance FET-based down- and up-converters. The performance of the proposed architecture is verified using experimental results. © 2009 Wiley Periodicals, Inc. Microwave Opt Technol Lett 51: 2882–2884, 2009; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/mop.24788
Microwave and Optical Technology Letters 11/2009; 51(12):2882 - 2884. · 0.62 Impact Factor
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ABSTRACT: A novel reconfigurable frequency translating antenna for cost-effective wireless transceiver applications is described. The integration of a dual transistor sub-harmonic mixing topology with a five-patch series arrangement enables the system to operate in resistive mode for reception or in active mode for transmission. The printed structure behaves as an antenna in the 1850 MHz frequency band and as a stepped-impedance lowpass filter. This avoids undesired radiation of the LO component and allows IF signal extraction in the down converting mode. Measured isotropic conversion gain (4.47 and 19.3 dB) supports the validity of the proposed solution in low-cost compact wireless transceiver applications.
Electronics Letters 02/2008; · 0.96 Impact Factor
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ABSTRACT: In this paper, a transmitting active array with spatial power combining concept for selective spatial linearization is implemented. The main nonlinearity of PHEMT device is used to describe some characteristics of its intermodulation distortion behaviour. An auxiliary branch is added for cancelling the third order intermodulation distortion (IMD3) of the main branch without diminishing its gain. A dual-feed series patch array was designed with a good input matching as well as acceptable port-to-port isolation. Experimental characterization of the complete system has proved an important cancellation of the IMD3 appears on the pointing direction comparing with the class A operation. These results validate the proposed method.
Antennas and Propagation, 2007. EuCAP 2007. The Second European Conference on; 12/2007
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ABSTRACT: In this paper, an unbiased mixing antenna for wireless receiver applications is proposed. Thanks to the proper integration of a resistive subharmonic mixer in a five-patch series arrangement, a -4.47 dB isotropic conversion losses was obtained without the need for batteries. The selected printed structure behaves not only as a 1850 MHz band antenna, but also as a stepped-impedance low-pass filter, rejecting the LO component while allowing the IF signal extraction. Unbiased operation is assured taking advantage of the low positive threshold voltage of Enhancement-mode PHEMT devices. Experimental results show the validity of the proposed solution for low cost and compact wireless reception.
Antennas and Propagation, 2006. EuCAP 2006. First European Conference on; 12/2006
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ABSTRACT: In this paper, an exhaustive study of different equivalent circuits of an aperture coupled patch permits to develop a suitable circuit model. The vast majority of these models are able to reproduce the antenna behavior around the first resonance frequency, but the proposed equivalent circuit is also capable of duplicating the radiator input impedance in the two next harmonics. Over such model two different approaches have been carried out for beamsteering purposes: a variable capacitor has been added to control the resonant frequency and a left-handed (LH) structure has been introduced at the patch input to obtain two variable operating bands. The agreement shown in the results obtained using the proposed circuit structure, electromagnetic simulations and experimental measurements validates the model. Furthermore, simulations and measurements over the resonance control show very promising results
Electrotechnical Conference, 2006. MELECON 2006. IEEE Mediterranean; 06/2006
