Aperture-coupled thin-membrane microstrip array antenna for beam scanning application

A microstrip array using an aperture-slot-coupling technique with very thin membranes has been developed at the L-band frequency for a beam scanning application. This technology-demonstration array with 4×2 elements achieved a relatively wide bandwidth of 100 MHz (8%) and ±45° beam scan. Very narrow coupling slots were used with each having an aspect ratio of 160 (conventional slot aspect ratio is between 10 to 30) for coupling through a very thin membrane (0.05 mm thickness). This thin-membrane aperture-coupling technique allows the array antenna elements to be more easily integrated with transmit/receive amplifier (T/R) and phase shifter modules. The paper addresses only the radiator portion of the array. The array and active components will be presented in a separate paper.