A new small size wideband impedance transformer

This paper presents a new microstrip transformer for the frequency range from 600 MHz up to 8 GHz, and for up to 3.5 GHz for meandered version. Overall dimensions of the meandered transformer are as low as 50 /spl times/ 10 mm. The circuit is designed for 100 to 50 Ohm impedance transformation. Two different concepts of meandered impedance transformer are presented. All types of the presented transformers achieve the reflection coefficient better than -20 dB in pass-band.