Designing a Cavity Backed Microstrip Antenna with Enhanced Isolation for the Development of a Continuous Wave Ground Penetrating Radar

This paper presents an improved design of a rectangular microstrip antenna at 920 MHz by backing it with an appropriate cavity wall to enhance the isolation between the transmitter and receiver antenna for use in applications, where the weak received power gets masked by the direct coupled power between two antennas. Antennas having 0.12 λ cavity wall with separation gap of 0.36 λ resulted in an isolation of 52.6 dB at a resonance frequency of 920 MHz with maximum and minimum isolation of 71.4 dB and 49.1 dB, respectively for 5% BW of the antenna designed. These antennas were fabricated and tested, which are used in the development of Continuous Wave Ground Penetrating Radar with an online graphical user interface; leading to the validation of the usefulness of proposed antennas. The isolation achieved at an optimised separation of the antennas enabled detection of metal targets as small as a bunch of wire buried 20 cm in the soil and non-metal, like wood and plastic buried in soil. It enabled the detection of a circular steel target of radius 12.5 cm buried at a depth of 65 cm in loose semi-dry pebbled soil

Through Wall Imaging Radar Antenna with a Focus on Opening New Research Avenues

This review paper is an effort to develop insight into the development in antennas for through wall imaging radar application. Review on literature on antennas for use in through wall imaging radar, fulfilling one or more requirements/specifications such as ultrawide bandwidth, stable and high gain, stable unidirectional radiation pattern, wide scanning angle, compactness ensuring portability and facilitating real-time efficient and simple imaging is presented. The review covers variants of Vivaldi, Bow tie, Horn, Spiral, Patch and Magneto-electric dipole antennas demonstrated as suitable antennas for the through wall imaging radar application. With an aim to open new research avenues for making better through wall imaging radar antenna, review on relevant compressive reflector antennas, surface integrated waveguide antennas, plasma antennas, metamaterial antennas and single frequency dynamically configurable meta-surface antennas are incorporated. The review paper brings out possibilities of designing an optimum through wall imaging radar antenna and prospects of future research on the antenna to improve radiation pattern and facilitate overall simple and efficient imaging by the through wall imaging radar

Low-Cost Simple Compact and Portable Ground-Penetrating Radar Prototype for Detecting Improvised Explosion Devices

This chapter presents the design and fabrication of a low-cost continuous-wave ground-penetrating radar for detecting improvised explosive devices buried in the soil for use of security forces. It is low cost and simple because it uses a single frequency (920 MHz) and is designed only for the detection of the buried target. The work presented includes designing of transmitter system module, receiver system module, antennas, power module, graphical user interface module, and making a prototype that is compact and portable. The chapter explains the concept and illustrates a method to enhance isolation between antennas, which is a very important parameter for the effective functioning of ground-penetrating radar. The presented method of enhancing isolation by cavity-backing a rectangular microstrip antenna and keeping them separated at an optimum gap yielded high isolation of 52.6 dB. The prototype radar, using the enhanced isolation antennas, demonstrates the capability to detect up to the depth of 65 cm for a circular steel target of radius 12.5 cm buried in loose semi-dry pebbled soil. The prototype radar is sensitive enough to detect a plastic box, a small bunch of wire, a book (paper) buried in soil and a wooden slab and a steel scale buried in a sandpit