r&s®zrc swr bridge, 40 khz to 4 ghz, 50 ω | 测试与测量 | option -九游官网下载
measurement of reflection coefficient from 40 khz to 4 ghz
- 概览
- features & benefits
measurement accuracy
the accuracy of a bridge is generally defined by its directivity and by multiple reflections between the dut and the measurement port. when measuring small reflection coefficients, the finite directivity is decisive. reflection coefficients that are smaller than the directivity can no longer be measured directly.
the measurement accuracy of large reflection coefficients mainly depends on the port matching of the bridge. at a directivity of d = 40 db, for example, and a return loss of the measurement port of s = 23 db, the maximum absolute error as a function of the reflection coefficient to be measured is 0.01 0.07 · |r|2.
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- maximum measurement uncertainty for a return loss s of 20 db and 23 db at the test port and directivity d of 40 db and 46 db
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- typical response and tolerance limits of return loss s at test port and directivity d of 50 ω bridge
the diagram above is ideal for assessing this quantitatively. the maximum positive and negative measurement uncertainty is plotted as a function of the measured return loss. the specified limit values of the r&s®zrc are used here. for the center frequency range of approx. 1 mhz to 1 ghz, both the return loss at the measurement port (typ. >28 db) and the directivity (typ. >50 db) are higher than specified. the measurement uncertainties that arise are smaller than the limit values shown and usually negligible during practical measurements.