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1、Amphenol RF Asia Connector Overview Training,May 5, 2003,Connector Anatomy,What is a Connector? A connector is a device used to connect to cables or other devices through which electromagnetic energy is transferred from one place to another Body-Contact-Insulator,Body,Contact,Insulator,Connector Ana
2、tomy,Discontinuity Compensation Steps,Dielectric Support Bead,Contact Barb,Slotted Contact,Cable Anatomy,What is Cable? Cable is a transmission line through which electromagnetic energy is propagated and transferred from one place to another Jacket-Braid-Shield-Dielectric-Center Conductor,Conductor,
3、Dielectric,Jacket,Shield,Braid,Assistance on the Web,Amphenol RF Newsletter Technical Questions: VSWR Conversion Charts: Glossary: ,# 1. Transmission Line,What is a transmission line? A transmission line is a conduit by which electromagnetic energy is transferred from one place to another Coaxial Ca
4、ble- Unbalanced Line: Center conductor surrounded by a concentric dielectric and outer conductor-Most popular type of transmission line,# 1. Transmission Line,What is a transmission line? A transmission line is a conduit by which electromagnetic energy is transferred from one place to another Wavegu
5、ide: Rectangular, Circular,# 1. Transmission Line,What is a transmission line? A transmission line is a conduit by which electromagnetic energy is transferred from one place to another Planar Transmission Line: Microstrip, Stripline, Coplanar waveguide are most common,# 1. Transmission Line,What is
6、a transmission line? A transmission line is a conduit by which electromagnetic energy is transferred from one place to another Twin Line- balanced line: two parallel conductors separated by a dielectric,. .,# 1. Transmission Line,The type of transmission line will determine the connector style Cable
7、 Connector-Coaxial Cable, Twin Line Surface Mount Connector-Microstrip Tab Launch Connector-Microstrip, Stripline, Coplanar End Launch Connector-Microstrip, Coplanar Pin Launch Connector-Microstrip, Stripline, Coplanar,# 2. Impedance,Ohms Law,# 2. Impedance,Impedance: The impedance of the connector
8、generally must match that of the transmission line Non-Constant 50, 75 ohm 50 ohm 75 ohm BNC Twinaxial BNC 7/16 1.6/5.6 UHF SMB C, SC, HN Type F Twinaxial MCX Mini-UHF Type G 1.0/2.3 MMCX TNC SMA N,Outer Diameter Inner Diameter Dielectric Constant Impedance .063 .020 2.0 50 Ohms .063 .012 2.0 75 Ohm
9、s .276 .120 1.0 50 Ohms,# 3. Frequency Range,Frequency is the number of electromagnetic waves that pass a given point in 1 second Hertz is the unit of frequency measurement Generally, the RF performance of a connector degrades as the frequency is increased (c=f) Wavelength decreases, therefore small
10、er disruptions cause more problems Specifying the frequency will make it easier for the design engineer to optimize the performance Whenever possible, dont specify a high frequency connector when a low frequency connector will work do the job,# 3. Frequency Range,Giga = 1,000,000,000 Billion Mega =
11、1,000,000 Million Kilo = 1,000 Thousand Milli = 1/1000 One thousandth Micro = 1/1,000,000 One millionth Nano = 1/1,000,000,000 One billionth Pico = 1/1,000,000,000,000 One trillionth,Frequency Chart (GHz),# 4. Return Loss or VSWR,A measure of how much power is reflected Return Loss: The portion of a
12、 signal that is lost due to a reflection of power at a line discontinuity. Return Loss is similar to VSWR and is generally preferred in the CATV industry to a VSWR specification VSWR: Acronym for Voltage Standing Wave Ratio. VSWR is the ratio of voltage applied to voltage reflected. It is the major
13、factor contributing to the total signal efficiency of the connector. Best performance is achieved when the impedance of the cable and the connector are the same (matched),Return Loss = Ratio of reflected to incident power in dB VSWR = Ratio of maximum to minimum electric field (Voltage),# 5. Inserti
14、on Loss,Insertion Loss is expressed in dB, and is a measure of the total loss of power going through a device IL = -20*log (Pout/Pin) Includes losses due to reflection (usually the dominant factor unless the Return Loss is very low -26 dB), plus losses due to the dielectric and metal conductors (Attenuation) Long Cable assembly-Connector insertion loss not usually significant Short cable assembly- Connector insertion loss can be significant Typically, connector insertion loss is very small (.1-.25 dB),
