A Basic Study on RF Characteristics of Meander Line Employing Periodic Ground Structure on GaAs MMIC for Application to Miniaturization of RF Components

The meander line employing periodic ground structure (MLEPGS) was fabricated on GaAs substrate for application to miniaturization of RF components on MMIC, and its RF characteristics were thoroughly investigated. The MLEPGS with a length of λ/8 showed loss less than 0.72 dB up to 20 GHz, which was low enough for application to RF passive components. The MLEPGS showed much higher propagation constant β and effective permittivity εeff than conventional meander line. Concretely, the MLEPGS with T of 20 μm showed β of 1.08~20.85 rad/mm and εeff of 2703~2479 from 1 to 20 GHz, while the conventional meander line showed β of 0.18~3.36 rad/mm and εeff of 74.2~64.7 in the same frequency range. According to the result, the size of the λ/4 transmission line employing the MLEPGS was 0.151 mm2, which was 3.5% of the size of the transmission line employing conventional meander line.