HIGH FREQUENCY DETECTION METHOD AND HIGH FREQUENCY DETECTION CIRCUIT

摘要

A high frequency detection circuit in accordance with the present invention detects information about a first high frequency power in a high frequency power source device supplying the first high frequency power having a first frequency (f) and a second high frequency power having a second frequency (f1) lower than the first frequency (f) to a load (7). A third high frequency signal (V1) that is a mixed signal of a first high frequency signal having the first frequency (f) and a second high frequency signal having the second frequency (f1) is detected by a directional coupler (12). The third high frequency signal (V1) is converted to a fourth high frequency signal (V1') having a third frequency ( DELTA f) between the first and second frequencies (f, f1) using a heterodyne system. A progressive wave power (Pf) of the first frequency (f) is detected based on the fourth high frequency signal (V1'). <IMAGE>