Planar Differential Antenna for Short-Range UWB Pulse Radar Sensor

Abstract

Abstract-A novel planar differential ultra-wideband (UWB) antenna was designed and implemented on low-cost FR4 substrate and characterized experimentally. The dedicated design was motivated by the implementation of a UWB pulse radar sensor obtained by co-integrating a system-on-a-chip UWB pulse radar packaged in QFN32 package with the proposed antenna, one for the transmitter and one for the receiver. The experimental results confirm the predictions obtained by simulations, and the effectiveness of the novel antenna design for the implementation of low-cost short-range pulse radar sensor was validated by field operational tests.Index Terms-Ultra-wideband (UWB), planar antenna, differential antenna, short-range radar, biomedical applications. . UWB devices transmit and receive extremely short radio-frequency pulses, with time duration in the range from tens of picoseconds to tens of nanoseconds. As a consequence, the frequency spectrum of the transmitted signal has very wide band occupancy (several GHz) and very low power spectral density (PSD). The maximum in-band (3.1-10.6 GHz) allowed equivalent isotropic radiated power (EIRP) spectral density is -41.3 dBm/MHz. According to the FCC definitions, a UWB system is any radio system operating in a bandwidth greater or equal to 500 MHz, or with a fractional band greater or equal to 10%, operating in the above spectrum region. This is a key enabling radio technology for several unlicensed commercial applications, such as ground penetrating radar (GPR) systems, wall and through wall imaging systems, surveillance systems, high data rate Recently the first system-on-a-chip (SoC) UWB pulse radar, operating in compliance with the FCC mask, was implemented in 90 nm CMOS technology by our research group [2]. The entire UWB pulse radar sensor was implemented by co-integrating the radar microchip above and two novel planar differential antennas (transmitting and receiving) designed and realized on FR4 substrate. This paper addresses the design, simulation and experimental characterization of the novel UWB antenna, which was not reported in our previous publications focused exclusively on the SoC implementation of the radar microchip [2], and on the functional and field operational tests for respiratory rate detections [3], whose results will be not repeated here.The paper is organized as follows. Section II reports the description of the novel antenna design. Section III, reports the results of simulations and measurements. Finally, in Section IV, the conclusions are drawn.

UWB pulse radio transceivers and antennas: Considerations on design and implementation

“…The antenna gain amounts to about 2.4 dBi. All these results have been confirmed by measurements carried out in anechoic chamber and reported in [8].…”

“…A set of functional and field operational tests for contactless detection of respiratory rate were reported in [6]. The design and experimental characterization of the planar differential antenna implemented on FR4 laminate was reported in [7,8]. Therefore, most of the details associated to these aspects will be not repeated herein.…”

Editors' Choice—Review—Semiconductor Integrated Radar for Sensing Applications

“…The operational tests carried out within a distance radar-target within one meter have shown the detection of sub-centimeter spatial resolution and respiratory rate patterns in adults (both genders) and infant volunteers, including apnoea. These results have been obtained by means a compact radar sensor with novel low-cost planar antennas, [48][49][50] as shown in Fig. 21, without adopting complex and bulky three-dimensional structure antennas more directive and with superior performances.…”

An H-Shaped Differential Fed Patch Antenna for a Gan Base Station Transmitter

“…Microstrip antennas, owing to their small size, high gain, low profile, low cost, and ease of fabrication, represent good candidates for wireless communication, where differential input/output is needed [6 7]. Research efforts have been focused on developing microstrip patch antennas with improved gain and efficiency [7][8][9][10][11][12]. However, most of them follow stacked or low temperature co-fired ceramics (LTCC) layers rendering the whole system complicated and expensive [8][9][10][11][12][13][14][15].…”