Serial Patch Array Antenna for an FMCW Radar Housed in a White Cane

Abstract

The design, realization, and test of the transmitting and receiving antennas for an FMCW radar operating between 24 and 24.25 GHz (ISM band), to be housed in a white cane for improving mobility of visually impaired subjects, have been performed. The coaxial-to-microstrip transition necessary for feeding the antennas has been studied together with the characteristics of serial arrays of increasing number of patches. Based on this study, a serial array with 8 patches has been selected for the transmitting and receiving antennas. The realized structures show a reflection coefficient lower than −10 dB in the ISM band. When the antennas are attached to an FMCW radar board, the radar is able to record reflections from a metallic panel up to a 5 m distance.

An Overview of Assistive Devices for Blind and Visually Impaired People

“…Results of small-sample experiment containing two human subjects showed that the RFID-based smart cane has a potential to help VIPs and blind people to walk independently in indoor environments. Frequency-modulated continuous wave (FMCW) radars and antennas were housed in a classic white cane by Pisa et al [89] for obstacle detection. The result showed that this cane could receive reflections from a metallic panel up to 5 m. FMCW radar is a short-range measuring radar set capable of determining the distance of object in its view field.…”

Insight on Electronic Travel Aids for Visually Impaired People: A Review on the Electromagnetic Technology

“…Solutions employing 24 GHz radars based on FMCW modulation are presented in [21][22][23], but different choices were made concerning the way the users employ the devices. The clinical investigation was implemented during an observation period of two weeks, using the electromagnetic aid during everyday activities.…”

“…Solutions employing 24 GHz radars based on FMCW modulation are presented in [21][22][23], but different choices were made concerning the way the users employ the devices. For both graphs in Figure 6, the answers recorded on the X-axes are: (1) not at all, (2) not much, (3) to some extent, (4) significantly, (5) very significantly.…”

“…In the results, 92% of the participants stated that the perception of the surrounding environment was enhanced by the electromagnetic aid, whereas 80% noticed an increased confidence in independent mobility. Solutions employing 24 GHz radars based on FMCW modulation are presented in [21][22][23], but different choices were made concerning the way the users employ the devices.…”

“…Most aids are radar-based systems, where the frequency-modulated continuous wave (FMCW) is the typical mode of operation [19][20][21][22][23][24][25]. In a FMCW radar, the information about the target is contained in the frequency of the received signal.…”