Low-Profile Directional Ultra-Wideband Antenna for See-Through-Wall Imaging Applications

Abstract

Abstract-A compact-size planar antenna with ultra-wideband (UWB) bandwidth and directional patterns is presented. The antenna can be fabricated on a printed circuit board (PCB). On one side of the PCB, it has a circular patch, and on the other side it has a slot-embedded ground plane with a fork-shaped feeding stub in the slot. Directional radiation is achieved by using a reflector below the antenna. To reduce the thickness of the antenna, a new low-profile antenna configuration is proposed. Three types of directional UWB antennas are analyzed. The distance between the antenna and the reflector is 12 mm (0.16λ 0 , λ 0 is the free space wavelength at the lowest frequency). In order to validate the design, a prototype is also fabricated and measured. Measured results agree well with the simulated ones. The measured results confirm that the proposed antenna features a reflection coefficient below −10 dB over the UWB range from 4.2 GHz to 8.5 GHz, a maximum gain around 9 dBi, a front-to-back ratio over 17 dB and pulse fidelity higher than 90% in the time domain. Thus it is promising for see-through-wall imaging applications.

A Novel Rectangular Ring Planar Monopole Antennas for Ultra-Wideband Applications

“…A reflector is used to achieve the high gain. A microstrip UWB antenna is presented in [8] with size of 34 mm×36 mm×1.6 mm, operated only from 4.6 GHz to 9.6 GHz. The detailed comparison with other antennas presented in [9][10][11][12][13][14][15][16][17][18][19][20][21][22][23] is given in Table 1.…”

“…Only designs in [9,16], and [21] have smaller areas than the proposed antenna, but with larger volumes, lower gains, and smaller bandwidths. [7] 30 × 34 × 12 9 1020 67.7 [8] 36 × 34 × 1.6 4.95 1224 70.4 [9] 15 × 33 × 5 4.15 495 120 [10] 100 × 100 × 0.762 5 10000 88.8 [11] 50 × 50 × 0.5 5 2500 70.7 [12] 32 × 35 × 1.5 5.9 1120 107.2 [13] 60 × 30 × 1.6 2.2 1800 142 [14] 32 × 40 × 0.76 3 1280 109.4 [15] 106 × 85 × 0.8 5 9010 163.6 [16] 25 × 28.5 × 1.27 --712.5 80.5 [17] 46.13 × 34.9 × 0.43 --1608.8 109.4 [18] 51.2 × 62 × 0.76 3 3174 85.7 [19] 57 × 77 × 0.76 6.98 4389 109.4 [20] 28.5 × 28 × 0.8 2.99 798 110. [21] 18 × 36 × 11 3.5 648 110 [22] 28 × 29 × …”

A New Method for Non-Line-of-Sight Vital Sign Monitoring Based on Developed Adaptive Line Enhancer Using Low Centre Frequency Uwb Radar

“…To improve the penetrability of nonmetallic obstacle, ultra-wideband (UWB) radar has been employed to detect vital sign of the victims in the NLOS scenes [9][10][11][12][13][14][15][16]. In these scenes, it mainly focuses on whether the victim is alive [16][17][18][19][20][21][22][23], namely life detection. It is realized based on accumulation of energy in a period of time, and signal-to-noise ratio (SNR) of vital sign can be improved.…”

Investigation of the Existence of Thermal Insulations in Wall Systems of Building Envelopes Using Uwb Technique

“…Localizing objects behind a wall can be done by various processing methods performed on the received response signals. Ultra-wideband (UWB) signal technology was the main method used [16][17][18][19][20][21][22]. Previously, there were some attempts to use Wi-Fi technology [23].…”

“…In both cases, there is no adequate information that can be extracted from the reflected or passed signals that can indicate the nature of materials inside an object. Seeing through a wall is largely based on recording received signals reflected from moving objects located behind that wall with or without known characteristics [16][17][18][19][20][21][22]. Localizing objects behind a wall can be done by various processing methods performed on the received response signals.…”