Agilent Connector Pin Recession and its Effect on Network Analyzer Accuracy - White Paper 5991-1227EN c20140 free download

File name Connector Pin Recession and its Effect on Network Analyzer Accuracy - White Paper 5991-1227EN c20140

Keysight Technologies Connector Pin Recession and its Effect on Network Analyzer Accuracy White Paper Abstract The apparent effect of a recessed connector upon network analyzer measurements is often talked about, but without any quantitative measurements it is very hard to either predict or correct for the resulting errors. This article outlines an experiment undertaken to assess the impact on the measurement of reflection coefficient when using 3.5 mm connectors. Introduction The ideal connector would not produce any discontinuities in the transmission line. In reality, as a result of their dimensional tolerances, there will normally be some small gap between mated connectors. This gap is often referred to as recession and it may be both or just one of the mated connectors which are recessed. The opposite of recession, protrusion, is likely to cause mechanical damage to 3.5 mm devices unless the mating connector is at least equally recessed and is undesirable. The electrical effect of recession is to produce a very short section of line having different impedance characteristics due to the difference in diameter of the center conductor and the exposed part of the connecting male pin. The theoretical effect of this change in diameter could be calculated but because there are many more effects in operation with such a short length of line, it is simpler to assess practically. Pin recession Mating end of connector Pin protrusion Figure 1. Connector recession defined This white paper may contain references to HP or Hewlett-Packard. Please note that Hewlett-Packard's former test and measurement and chemical analysis businesses are now part of Keysight Technologies. Some of the products mentioned may be obsolete or have been replaced by Keysight products. Procedure The measurements were performed using an HP8722D Vector Network Analyzer over the range 3 GHz to 27 GHz at 1601 trace points and with the bandwidth set to 300 Hz. Calibration (network analyzer error correction) was performed using an HP85052B Precision-grade Calibration Kit. Three separate calibrations were performed; first with the sliding load set to zero recession, another with it locked at 2.5 thousandths of an inch (0.0025") recession, and finally with 0.005" recession. It was important that the characteristics of the item to be measured remained stable throughout the test, even though the connector's pin recession was to be varied. The item selected for this task was another 3.5 mm sliding load (HP911D); the type where the connector recession can be adjusted using a small screwdr