The APC-7 connector (also referred to as a 7 mm connector) is a precision coaxial connector used on
laboratory
A laboratory (; ; colloquially lab) is a facility that provides controlled conditions in which scientific or technological research, experiments, and measurement may be performed. Laboratory services are provided in a variety of settings: physic ...
microwave
Microwave is a form of electromagnetic radiation with wavelengths ranging from about one meter to one millimeter corresponding to frequencies between 300 MHz and 300 GHz respectively. Different sources define different frequency ra ...
test equipment for frequencies up to 18
GHz
The hertz (symbol: Hz) is the unit of frequency in the International System of Units (SI), equivalent to one event (or cycle) per second. The hertz is an SI derived unit whose expression in terms of SI base units is s−1, meaning that one he ...
. APC-7 connectors are advantageous because they have a low-
reflection coefficient
In physics and electrical engineering the reflection coefficient is a parameter that describes how much of a wave is reflected by an impedance discontinuity in the transmission medium. It is equal to the ratio of the amplitude of the reflected w ...
, make repeatable
coaxial
In geometry, coaxial means that several three-dimensional linear or planar forms share a common axis. The two-dimensional analog is ''concentric''.
Common examples:
A coaxial cable is a three-dimensional linear structure. It has a wire condu ...
connections, and are
genderless.
The connectors are expensive, so they are seldom used outside the laboratory where their cost can be justified by their accuracy and convenience. Due to their high cost, their 18 GHz frequency limitation, and new laboratory practices,
[Connections at the instrument front panel don't need to be repeatable because those connections remain mated during tests. Modern network analyzers focus on the reference plane near the device under test and have features such as automated calibration, adapter removal, and models for calibration references. The advantages of the APC-7 connector have been diminished.] the connectors are now uncommon. Modern low frequency microwave equipment often uses the less expensive 3.5 mm (26.5 GHz) connector. Higher frequency equipment must use higher performance connectors such as the 2.92 mm (40 GHz), 2.4 mm (50 GHz), 1.85 mm (67 GHz), or 1.0 mm (110 GHz) connectors.
Features
APC-7 connector pairs have several desirable features:
* The connectors are genderless. This avoids some awkward adapters or duplication of laboratory standards. With a gendered connector, a laboratory might need a precision male load and a precision female load. With a genderless connector, only one load is required. Although the illustration shows threads on one connector of the pair, the (male) threaded ring can be screwed back to leave a female screw thread.
* The connectors have a well-defined reference plane. Consequently, the connectors simplify some measurements.
* The mated pair of APC-7 connectors has a low reflection coefficient and thus low
voltage standing wave ratio (VSWR). The low reflection coefficient means better measurement accuracy. The typical VSWR is 1.025:1 at 18 GHz.
* The mated pair makes a repeatable connection. A pair has a repeatable reflection coefficient to ±0.001.
Consequently, laboratory measurements have reduced uncertainty.
Adapters
APC-7 connectors require adapters to change from the connectors used in the laboratory to those used on everyday products. These adapters are expensive precision devices. For example, an APC-7 to type N (f) cost $105 in 1979.
Such adapters bought new today (as of July 2012) can cost as much as $294.
History
"APC" stands for
Amphenol
Amphenol Corporation is a major producer of electronic and fiber optic connectors, cable and interconnect systems such as coaxial cables. Amphenol is a portmanteau from the corporation's original name, American Phenolic Corp.
History
Amphenol ...
Precision Connector and "-7" for 7 millimetres.
Hewlett-Packard started developing the connector in the mid-1960s. Amphenol improved the design and manufactured the connector.
Notes
References
External links
*http://www.rosenberger.de/ok/images/documents/spez/07.pdf
nactive - 4 Feb 2019Rosenberger RPC-7 document that shows interface dimensions; RPC is Rosenberger's designation for its APC-7 connector
*https://web.archive.org/web/20170707175918/http://www.rosenberger.de/ok/images/documents/spez/07.pdf
ctive - 4 Feb 2019*https://www.rosenberger.com/0_documents/de/specs/tm/07.pdf
ctive - 4 Feb 2019
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RF connectors