Patent ID: 7498907

Claim:
A transmission line substrate that transmits a driving control signal input to and output from a semiconductor device, the transmission line substrate comprising a spurious-wave suppression circuit that includes a divider that divides a signal line connected to the semiconductor device into first and second signal lines of the same phase; a delay unit that is connected to the first signal line and includes a signal line with a length of substantially one half of an in-substrate effective wavelength of a spurious wave in a microwave band and a millimeter-wave band; two parallel two lines that includes third and fourth signal lines in parallel, on which spurious waves are in opposite phases, the third signal line being connected to the delay unit and the fourth signal line being connected to the second signal line; a resistor that is located on the two parallel lines and connects between the third and fourth signal lines; and a combiner that combines the third and fourth signal lines in the same phase.