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This paper presents an inverse Chebyshev filter for channel selection in the baseband section of an extravehicular activity (EVA) fully integrated radio receiver. The filter is synthesized from a 4 th order doubly-terminated LC ladder prototype using a leapfrog structure in order to minimize the use of active components. The cutoff frequency of the filter is digitally controlled for different channel bandwidths through a binary weighted capacitor bank that allows tuning from 1.1 MHz to 2.28 MHz. The derivation of the filter specifications from the system level parameters of the EVA radio receiver is presented. Also, the impact of the channel selection filter in the overall receiver performance is discussed. The circuit is implemented using the IBM 0.18 µm standard process and postlayout simulations show a pass-band gain of -0.07 dB, an IIP3 of 38 dBm, adjacent channel rejection better than 50 dB and a noise figure of 30.2 dB. The filter operates from a 1.8 V power supply consuming 4.03 mA.

The design, implementation and testing of a wireless medical system (WMS) for continuous monitoring of biological parameters are presented in this paper. Special emphasis has been made on the implantable unit prototype.The proposed system consists of three main sections: implantable medical device (IMD), base station (BS) and graphical user interface. The IMD and BS communicate through an RF link that operates in both the industrial, scientific and medical (ISM, at 2.4-2.48 GHz) and the medical implantable communication service (MICS, at 402-405 MHz) bands. The IMD and BS are based on two commercially-available ultra-low power integrated circuits: a mixed-signal microcontroller and a medical implantable radio transceiver. A comprehensive explanation of the main design issues and implementation challenges is presented. The details regarding the analog front-end functionality, a low-power-oriented algorithm, an analysis of power consumption versus lifetime and a customized operating mode for power optimization are explained. The main considerations for link budget calculations in implantable applications are discussed. A test bench designed to emulate real conditions is used to verify the functionality of the WMS showing successful communication up to 2.1 m range with a data rate of 200 Kbps. The IMD works from a 3 V power supply with an average current consumption of 0.572 mA (including RF transmission) in continuous operation. This allows a 2 year IMD lifetime in periodic operation (for a 350 mAh battery), delivering 1 h of information per day.

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This paper presents a wireless medical system (WMS) for continuous monitoring of biological parameters with special emphasis on the implantable unit prototype. The proposed WMS consists of three subsystems: implantable medical device (IMD), base station (BS) and graphical user interface (GUI). The IMD and BS communicate through an RF link that operates in both the industrial, scientific and medical (ISM, at 2.4GHz-2.48 GHz) and the medical implantable communication service (MICS, at 402MHz-405MHz) bands. The IMD and BS are based on two commercially-available ultra-low power integrated circuits. The main design issues and implementation challenges are discussed. Details on the analog front-end, a low-poweroriented-algorithm, an analysis of power consumption vs. lifetime and link budget considerations for implantable applications are presented. In vitro measurements of the WMS show successful communication up to 2.1m. The IMD average current consumption is 0.572mA (including RF transmission) in continuous operation. This allows a two year IMD lifetime in periodic operation, delivering one hour of information per day.