How to select a right RF connector?

Radio frequency connector, also known as RF connector, is usually considered to be a component attached to a cable or installed on an instrument. It serves as a component for electrical connection or separation of transmission lines and mainly serves as a bridge.

Classification by size:

. Standard type: UHF, N, 7/16, 7mm;

. Small size: BNC, TNC;

. Ultra-small: SMA, SMB, SMC, MCX, BMA, SAA, 3.5mm;

Micro: SSMA, SSMB, MMCX, 2.4mm. K (2.92mm), 1.85mm, 1mm;

Below is key factor you need to take into consideration when select a satisfying RF connector.

Genearally, the main indicators of RF connectors are:

1. Impedance: Almost all RF connectors and cables are standardized to 50ohm impedance, the only exception is the 75ohm cable TV connector to transmit video signal. It is also imperative that the coaxial connector terminated to the cable matches the cable impedance.

2.Voltage standing wave ratio, VSWR in short, is an indicator used to describe the degree of signal reflection on a transmission line. It is defined as the ratio of the maximum voltage to the minimum voltage on the transmission line. The smaller the value of VSWR, the higher the efficiency of signal transmission, and vice versa, the greater the reflection loss.

Generally, within the frequency range of concern, the VSWR is guaranteed to be less than 1.2, but this is not necessarily the case. To reach 12, some are satisfied with 1.5 or 2 below. Of course, the lower, the better, and the cost will be correspondingly higher.

3.Frequency range: The operating frequency range of RF connectors must be paid attention to in the high-frequency and high-speed fields. The frequency is divided into several grades, such as 1-6GHz, or 0-18GH, 20GHz.27GH2, 40GH2, 50GHZ, 67GH2, 110GHz or higher.

4.Cycling life: It is generally considered the plugging and unplugging reaching to certain times the performance of the connector cannot be guaranteed. Generally, the plug-and-pull times of RF connectors are 500 or 1,000 times, and there are also higher requirements.

The disconnection you have to do it under a specific torque, otherwise it will be difficult to guarantee the number of uses. Proper torque will

5.Insertion loss (IL) refers to the power loss  on the line due to the RF connectors introduction. It is ratio of output power to input power. There are many factors that increase connector insertion loss,  typically are mismatch of characteristic impedance, inaccurate assembly, interface gap, axial slant, lateral offset, eccentricity, machining and plating, etc.