APC-7 connector
Encyclopedia
The APC-7 connector is a precision coaxial connector that was used on laboratory
microwave
test equipment for frequencies up to 18 GHz
. APC-7 connectors were advantageous because they have a low-reflection coefficient
, make repeatable coaxial
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, 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), or 1.0 mm (110 GHz) connectors.
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. Companies will often change the first letter of the acronym to match theirs, for example, RPC-7 from Rosenberger Micro-Coax. To address this, the abbreviation GPC-7 was designated to mean "General Precision Connector-7".
LPC-7 (Laboratory Precision Connector-7) refers to inner conductors with only air dielectric
s. This means that LPC-7 can only refer to unsupported air lines.
As GPC-7 started to be used for lower grades of the same type, a catch all of PC-7 (Precision Connector-7) is now often used.
Laboratory
A laboratory is a facility that provides controlled conditions in which scientific research, experiments, and measurement may be performed. The title of laboratory is also used for certain other facilities where the processes or equipment used are similar to those in scientific laboratories...
microwave
Microwave
Microwaves, a subset of radio waves, have wavelengths ranging from as long as one meter to as short as one millimeter, or equivalently, with frequencies between 300 MHz and 300 GHz. This broad definition includes both UHF and EHF , and various sources use different boundaries...
test equipment for frequencies up to 18 GHz
GHZ
GHZ or GHz may refer to:# Gigahertz .# Greenberger-Horne-Zeilinger state — a quantum entanglement of three particles.# Galactic Habitable Zone — the region of a galaxy that is favorable to the formation of life....
. APC-7 connectors were advantageous because they have a low-reflection coefficient
Reflection coefficient
The reflection coefficient is used in physics and electrical engineering when wave propagation in a medium containing discontinuities is considered. A reflection coefficient describes either the amplitude or the intensity of a reflected wave relative to an incident wave...
, make repeatable coaxial
Coaxial cable
Coaxial cable, or coax, has an inner conductor surrounded by a flexible, tubular insulating layer, surrounded by a tubular conducting shield. The term coaxial comes from the inner conductor and the outer shield sharing the same geometric axis...
connections, and are genderless
Gender of connectors and fasteners
In electrical and mechanical trades and manufacturing, each half of a pair of mating connectors or fasteners is conventionally assigned the designation male or female...
. 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, 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), 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.
- 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 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 coefficent to ±0.001. Consequently, laboratory measurements have reduced uncertainty.
Adapters
The APC-7 connector required 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.History
"APC" stands for AmphenolAmphenol
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....
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. Companies will often change the first letter of the acronym to match theirs, for example, RPC-7 from Rosenberger Micro-Coax. To address this, the abbreviation GPC-7 was designated to mean "General Precision Connector-7".
LPC-7 (Laboratory Precision Connector-7) refers to inner conductors with only air dielectric
Dielectric
A dielectric is an electrical insulator that can be polarized by an applied electric field. When a dielectric is placed in an electric field, electric charges do not flow through the material, as in a conductor, but only slightly shift from their average equilibrium positions causing dielectric...
s. This means that LPC-7 can only refer to unsupported air lines.
As GPC-7 started to be used for lower grades of the same type, a catch all of PC-7 (Precision Connector-7) is now often used.