Patent ID: 8159290

Claim:
A test apparatus for testing a device under test that outputs, as an output signal, an amplitude-phase modulated signal having a level and a transition point phase selected from among a plurality of levels and a plurality of phases according to transmission data, the test apparatus comprising: a test signal output section that outputs a test signal to the device under test; a pattern generating section that generates an expected level, which is an expected value for a level of the output signal to be output from the device under test in response to the test signal, and an expected phase, which is an expected value for the transition point phase of the output signal; a comparing section that compares the output signal to a first comparison level, which is less than the expected level, before the expected phase, and compares the output signal to a second comparison level, which is greater than the expected level, and to a third comparison level, which is less than the expected level, after the expected phase; and a judging section that judges that the output signal matches the expected values on a condition that (i) the output signal is less than or equal to the first comparison level before the expected phase and (ii) the output signal is less than or equal to the second comparison level and greater than or equal to the third comparison level after the expected phase.