Miniaturized Low-Cost Phased-Array Antenna Using SIW Slot Elements

In this letter, a miniaturized C-band phased-array antenna based on a novel series-fed network is introduced. The series-fed network, radiating elements, and phase shifters are the main parts of the proposed phased-array antenna. In order to use the identical phase shifters, quarter-wavelength transformers are used in the design of the series-fed network. Furthermore, by choosing the proper place of the quarter-wavelength transformers, the distance between adjacent radiating elements is significantly reduced to
$0.33\lambda_{0}$
. To reduce mutual couplings between radiating elements, miniaturized negative-order substrate integrated waveguide (SIW) slot antennas are chosen as radiating elements. A low-cost and compact 4-bit composite right/left-handed (CRLH) phase shifter is used due to the capability of being placed in a series-fed network. The proposed low-cost phased-array antenna is fabricated on a single-layer printed circuit board (PCB), and good agreement between the simulation and measurement results is obtained. The beam scanning range is 38
$^{\circ}$
, and the impedance bandwidth of the phased-array antenna is 25 MHz at the center frequency of 5 GHz.