Open AccessNovel low profile ultra‐wideband capacitance loaded log‐periodic monopole array with reduced transverse dimension
Author(s) -
He Huan,
Chen Yikai,
Yang Shiwen
Publication year - 2019
Publication title -
iet microwaves, antennas and propagation
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.555
H-Index - 69
eISSN - 1751-8733
pISSN - 1751-8725
DOI - 10.1049/iet-map.2018.6012
Subject(s) - ground plane , transverse plane , physics , wideband , magnetic monopole , microstrip , capacitance , electrical impedance , phased array , optics , frequency band , antenna array , array data structure , antenna (radio) , impedance matching , electrical engineering , optoelectronics , engineering , structural engineering , electrode , quantum mechanics
A novel low profile log‐periodic array with vertically polarised end‐fire radiation patterns is proposed in this study. It totally consists of 22 antenna elements with three different types of monopole antennas. Specifically, conventional monopoles were utilised at the high end band, while monopoles with different types of top‐hat loadings were designed for lower frequency band operation. Shorting posts are strategically introduced to maintain a good impedance matching at the lower band. A folded microstrip line is printed on the back side of the ground plane to feed the array. The log‐periodic monopole array achieves a very low profile of 0.063 λ l , where λ l is the wavelength at the lowest operating frequency in free space. Moreover, the array also exhibits an extremely narrow width of 0.075 λ l in the transverse dimension, which makes the array an attractive candidate for phased array development along the transverse direction. A prototype of the array is fabricated. Measured results show that the array achieves a minimum realised gain of 4.5 dBi across a wide frequency band of 1.19–11.7 GHz (9.83:1).