Abstract-In this paper propagation losses of body implanted antennas are studied at the ISM bands of 433 MHz, 915 MHz, 2450 MHz and 5800 MHz. Two body models are used, one based on a single equivalent layer and the other based on a three layer structure, showing the advantages and limitations of each one. Firstly, the antenna pair gain at different implanted antenna depths is analyzed. Next, we show the effects of the thickness of the different body tissue layers. Finally, we discuss the consequences of using a coating layer to isolate the antenna from the harsh environment of the human body.

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This letter presents a novel monopole antenna design for efficient dual-band operation over the entire international wireless local area network (WLAN) frequency bands of 2.4-2.5 GHz (802.11b/g) and 4.9-5.875 GHz (802.11a/h/j). The design is based on the principle of out-of-band loading using a magnetic resonator whose natural frequency is chosen to lie between the lower and upper WLAN bands. The position of the resonator and the frequency of its natural resonance are chosen to produce more than 1 GHz wideband match in the 5 GHz band. The length of the monopole combined with the out-of-band resonator inductance determines the match in the 2.45 GHz band.Index Terms-Dual-band wireless local area network (WLAN), magnetic resonator, monopole antenna, universal WLAN.

Abstract-One of the main drawbacks of antenna integration on standard CMOS silicon substrates are the low radiation efficiency levels obtained due to the high silicon losses. This paper studies the use of micromachining techniques to remove silicon beneath the antenna as a solution to improve radiation efficiency. Several etching patterns are analyzed for different etching depths through simulations and measurements in order to find out which are the best ones for the micromachining process. Results are verified in two operating scenarios.

This work presents a methodology for designing microwave acoustic filters, based on two-port bulk acoustic wave resonators (also known as stacked crystal filters), with either Butterworth or Chebyshev response. The presented methodology makes it possible to design this type of filter without any optimization work, and, moreover, for its closed-form expressions design can be obtained. As a validation example, we address the design of a pair of filters for UMTS cellular phone handsets. The different simulations carried out show the good agreement between the transmission response of the designed filters and the theoretical response.

This article presents a number of general equations for the primary design and evaluation of a stack of two bulk acoustic wave resonators, a structure traditionally known as a stacked crystal filter. The reported equations are validated against the work of other authors, finding a very good agreement between the results. © 2009 Wiley Periodicals, Inc. Microwave Opt Technol Lett 51: 752–755, 2009; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/mop.24188