摘要:
A transmission line substrate comprises a spurious-wave suppression circuit 50 including: a divider 51 that divides a signal line of a driving control signal connected to a semiconductor device into two signal lines of the same phase; a delay unit 52 that is connected to one of the divided signal lines and includes a signal line with a length substantially one half of an in-substrate effective wavelength of a spurious wave; parallel two lines 53 that are connected to the delay unit 52 and the other one of the divided signal lines and have parallel two signal lines on which spurious waves have mutually reversed phases; a resistor 55 that is arranged on the parallel two lines 53 and that connects between the parallel two signal lines; and a combiner 54 that includes a signal line that combines the two signal lines of the parallel two lines 53 and that outputs a combined signal to the outside. The spurious-wave suppression circuit 50 suppresses leakage of a spurious component to the outside, within a high-frequency package, and efficiently power attenuates and absorbs the spurious wave, without affecting the transmission characteristic of a DC bias voltage and a control signal that are necessary.