Miniaturised broadband on-chip transformer employing PPGM on MMIC for application to low impedance transformation

Using a microstrip line employing periodically perforated ground metal (PPGM) on a GaAs monolithic microwave integrated circuit (MMIC), a highly miniaturised and broadband impedance transformer was developed for application to low impedance matching in broadband. Its size was 0.132 mm² on GaAs substrate, which was 2.3% of the one fabricated by a conventional microstrip line. The transformer showed good RF performance over a broadband including ultra-wideband. This is the first report of an on-chip broadband impedance transformer fabricated on MMIC.