校准件3.5mm 7mm问题请教

stillever

安捷伦的校准件3.5mm和7mm这个尺寸是什么意思
谢谢大家。

RFMDC

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7mm connector

RFMDC

两种不同的校准的接口：3.5mm就是SMA，7mm是另外一种。支持3.5mm的校准件有85052B,7mm有85050D.

7mm is followed:
The APC-7 (Amphenol Precision Connector - 7 mm) offers the lowest reflection coefficient and most repeatable measurement of all 18 GHz connectors. Development of this connector was a joint effort between HP and Amphenol which began in the early 1960s. This is a sexless (hermaphrodite) design and is the preferred connector for the most demanding applications, notably metrology and calibration. These connectors are designed to perform repeatably for thousands of interconnect cycles as long as the mating surfaces are kept clean. You will find these connectors on the front of some network analyzers.
SMA:
The SMA (Subminiature A) connector was designed by Bendix Scintilla Corporation and is one of the most commonly used RF/microwave connectors. It is intended for use on semi-rigid cables and in components which are connected infrequently. It takes the cable dielectric directly to the interface without air gaps. A few hundred interconnect cycles are possible if performed carefully. Care should be taken to join connectors straight-on. Prior to making a connection it is wise to inspect the female end to assure that the center socket is in good condition (fingers not bent or missing).  
A standard SMA connector is designed for interconnects to 12.4 GHz. Fortunately, a good SMA is usable to 18 GHz in most cables, and if well constructed with greater loss and lower return loss to 24 GHz. Most SMA connectors have higher reflection coefficients than other connectors available for use to 24 GHz because of the difficulty to anchor the dielectric support. Some manufacturers rate a special high quality version of an SMA that meets SMA standards as high as 26.5 GHz (The Johnson Field Replaceable SMA goes to 26.5 GHz, and the M/A-Com OSM extended frequency series goes to 27 GHz). Because an SMA with such quality can be repeatably manufactured, you will often see test equipment and components rated to exactly 26.5 GHz with SMA connectors as the primary interconnect. "SMA" connectors rated for frequencies higher than 27 GHz are really following other standards and are made to be compatible with the SMA geometries to allow mating with SMA. So called "precision SMA" connectors are available with a variety of designators (e. g.,  3.5 & 2.92 mm). When two SMA compatible connectors of different ratings are coupled, it is very likely that the performance of the lesser connector will prevail.  

Be advised that when mating a male SMA to a female "Precision SMA", to be sure that the SMA male is of professional manufacture, and to insert the male straight-on. If there is any doubt, it is wise to invest in an SMA Connector Gauge, and gauge the SMA male prior to mating. This advice does not apply to the connection of an SMA female to a 3.5 or 2.9 male. Such connections do need to be made with care and straight-on.

report

校准件，SMA和N型校准件的区别吧

report

校准件，SMA和N型校准件的区别吧

stillever

非常感谢您的帮助。