Broadband transmission line transformer
View Patent ↗A broadband transmission line impedance transformer performs impedance transformation with improved frequency response and efficiency across a wide operational bandwidth. In particular, the bandwidth of a transmission line 2:1 impedance transformer may be significantly increased by adding an additional compensating capacitor as an internal component between interconnected transmission lines. This capacitor effectively improves low frequency response for a given length of transmission lines and decreases mismatch in an entire frequency range. The overall bandwidth ratio increases at least twice and mismatch decreases.
1. A transformer having enhanced frequency response, comprising:
a balun transformer comprised of a pair of interconnected four conductor transmission lines, said balun transformer having an input port and a balanced output port; and
two compensating capacitors coupled inside the balanced part of the transformer;
wherein the compensating capacitor improves low frequency response and decreases mismatch in an entire frequency range.
2. The transformer according to claim 1 , wherein the input port is unbalanced.
3. The transformer according to claim 1 , wherein the balun transformer includes a connection to ground.