| 摘要 |
PROBLEM TO BE SOLVED: To obtain a test signal with high quality at a small cost by power- amplifying a combined modulation signal, resulting from applying orthogonal transformation to a combined base-band signal outputted from a band-stop filter, so as to obtain a combined test signal. SOLUTION: An in-phase component Res1 (m)-sk (m) and a quadrature component Ims1 (m)-sk (m) of each of base-band signals s1 (m)-sk (m) which are outputted from each gain adjustment device 12 and whose gain is adjusted are given to digital signal adders 14a, 14b. Each of band stop filters 15a, 15b limits a pass frequency band of each of combined base-band signals ReS(m) and ImS(m) into a prescribed frequency band. An orthogonal modulator 18 applies orthogonal modulation processing to each of received analog combined base band signals ReS(t), ImS(t), based on a local oscillation signal from a local oscillator 17 to provide an output of an analog combined modulation signal S(t). The combined modulation signal S(t) is given to a power amplifier 19, where the signal is power-amplified, and a resulting combined test signal R(t) is outputted to the outside. |
