Blog

Semi-Rigid Coax Selector Guide

P1dB semi-rigid coax is used to build semi-rigid assemblies for test equipment, aerospace, wireless, medical and low PIM applications.  The advantage of semi-rigid coax over flexible coax is its increased phase stability and lower insertion loss.  Semi-rigid coax also provides the best electrical isolation and lower noise levels when compared to flexible coax.semi-rigid-assembly

Another advantage of semi-rigid coax is that it can be bent into and hold intricate shapes to accommodate complex cable runs, such as inside a chasis.  Semi-rigid is very durable and can survive harsh shock and vibration environments, such as a jet fighter or a missile. It can also handle large temperature swings, depending on the coax dielectric.

P1db Semi-rigid is available in 10 Ohm, 17 Ohm, 25 Ohm, 50 Ohm, 75 Ohm and 93 Ohm impedances with solid PTFE, low density PTFE (LD PTFE) or FEP dielectric.  The diameters available are .031 inch, .034 inch, .047 inch, .070 inch, .085 inch, .118 inch, .130 inch, .141 inch and .250 inch with a bare copper, tinned copper, silver plated copper, tinned aluminum or stainless steel outer conductor.  Two types of center conductors are offered, which are silver plated copper (SPC) easier bending or silver plated copper clad steel (SPCW) for high vibration applications.  All raw semi-rigid coax types are sold in straight sections, depending on the coax diameter.  Check the individual semi-rigid coax page for its specific straight-section length.

Semi-Rigid Features

  • Impedance values from 10 to 93 Ohms
  • Diameters from .031 inches to .250 inches
  • Standard (PTFE and FEP) and low loss (LD PTFE) version
  • Outer Conductor options from Bare Copper, Tinned Copper, Tinned Aluminum and more
  • Semi-Rigid Coax is sold in 1 to 2 meter lengths, depending on the coax diameter

Phase matched cables are offered in both flexible and semi-rigid coax, but semi-rigid offers the best performance and stability.  This is because semi-rigid coax will not flex, therefore phase-over-flexure errors on non-existent.  Their ability to hold a shape, phase stability and their high power capability are reasons why these cables are also preferred for coaxial baluns and transformers in applications, such as in a high power RF amplifier or pallet.

P1dB has a large selection of semi-rigid coax at a very competitive price.  The types of coax are shown below in 3 categories, .085 and .141 50 Ohm Coax, More 50 Ohm Coax Diameters, and Other Impedance Coax.  Select from the 3 categories of semi-rigid below

.085 and .141 Diameter, 50 Ohm Semi-Rigid Table click here

More 50 Ohm Semi-Rigid Diameters Table click here

Other Impedance Semi-Rigid Table click here

 

 

 

semirigid-coax-defined

.085 and .141, 50 Ohm Coax – The most common diameters for semi-rigid cable assemblies, due to a wide selection of connectors.  Bare copper outer conductor is the most common type, but many customers prefer tinned copper for its solder-ability when assembling their own cables.  For situations where increased conductivity is needed, then Silver plated copper is the best choice.  Metals other than copper are also available, such as Tinned Aluminum for weight concerns and Stainless Steel for harsh environments.  There are two choices for a dielectric, PTFE for common applications and LD PTFE for low loss requirements.

Part Number Impedance (Ω) Diameter (in.) Outer Conductor Center Conductor Dielectric
 P1CB-050-085-CUSP-L  50  .085  Bare Copper SPC  LD PTFE
 P1CB-050-085-CUSW-P 50  .085 Bare Copper SPCW PTFE
 P1CB-050-085-SPSP-L
50 .085  Silver Plated Copper SPC  LD PTFE 
 P1CB-050-085-SPSW-P 50 .085  Silver Plated Copper SPCW PTFE 
 P1CB-050-085-SSSW-P 50 .085  Stainless Steel SPCW PTFE 
 P1CB-050-085-TASP-L 50 .085 Tin Plated Aluminum SPC  LD PTFE 
 P1CB-050-085-TASW-P 50 .085 Tin Plated Aluminum SPCW PTFE 
 P1CB-050-085-TPSP-L 50 .085 Tin Plated Copper SPC  LD PTFE 
 P1CB-050-085-TPSW-P 50 .085 Tin Plated Copper SPCW PTFE 
P1CB-050-141-CUSP-L 50 .141 Bare Copper SPC   LD PTFE 
P1CB-050-141-CUSW-P 50 .141 Bare Copper SPCW   PTFE 
P1CB-050-141-SPSP-L 50 .141 Silver Plated Copper SPC   LD PTFE 
P1CB-050-141-SPSW-P 50 .141 Silver Plated Copper SPCW  PTFE  
P1CB-050-141-SSSW-P 50 .141  Stainless Steel SPCW  PTFE 
P1CB-050-141-TASP-L 50 .141 Tin Plated Aluminum SPC   LD PTFE 
P1CB-050-141-TASW-P 50 .141 Tin Plated Aluminum SPCW  PTFE  
P1CB-050-141-TPSP-L 50 .141 Tin Plated Copper SPC   LD PTFE 
P1CB-050-141-TPSW-P 50 .141 Tin Plated Copper SPCW  PTFE  

 

 

 

 

pigtail

More 50 Ohm Coax Diameters – Higher frequencies, such as 60 GHz, require small diameter coax with higher maximum frequencies.  Fore example, a .047 diameter cable has a maximum frequency of 109 GHz, while a .250 diameter coax has a max frequency of 19 GHz.  The trade off is choosing as large of a diameter as possible to reduce insertion loss while not exceeding a coax cables max frequency.  A popular use for small diameter coax is in pigtails for use as an RF probe within a circuit for testing purposes.

Part Number Impedance (Ω) Diameter (in.) Outer Conductor Center Conductor Dielectric
 P1CB-050-031-CUSP-L  50 .031 Bare Copper SPC  LD PTFE
 P1CB-050-031-TPSP-L 50 .031 Tin Plated Copper SPC  LD PTFE
 P1CB-050-034-CUSW-P 50 .034 Bare Copper SPCW PTFE
 P1CB-050-034-SPSW-P 50 .034 Silver Plated Copper SPCW PTFE
 P1CB-050-034-TPSW-P 50 .034 Tin Plated Copper SPCW PTFE
 P1CB-050-047-CUSW-P 50 .047 Bare Copper SPCW PTFE
 P1CB-050-047-SPSW-P 50 .047 Silver Plated Copper SPCW PTFE
 P1CB-050-047-SSSW-P 50 .047 Stainless Steel SPCW PTFE
 P1CB-050-047-TASP-L 50 .047 Tin Plated Aluminum SPC  LD PTFE
 P1CB-050-047-TASW-P 50 .047 Tin Plated Aluminum SPCW PTFE
 P1CB-050-047-TPSW-P 50 .047 Tin Plated Copper SPCW PTFE
 P1CB-050-070-CUSP-P 50 .070 Bare Copper SPC PTFE
 P1CB-050-070-SPSP-P 50 .070 Silver Plated Copper SPC PTFE
 P1CB-050-118-CUSW-L 50 .118 Bare Copper SPCW  LD PTFE
 P1CB-050-118-SPSW-L 50 .118 Silver Plated Copper SPCW  LD PTFE
 P1CB-050-118-TPSW-L 50 .118 Tin Plated Copper SPCW  LD PTFE
 P1CB-050-250-CUSP-P 50 .250 Bare Copper SPC PTFE
 P1CB-050-250-SPSP-P 50 .250 Silver Plated Copper SPC PTFE
 P1CB-050-250-TASP-P 50 .250 Tin Plated Aluminum SPC PTFE
 P1CB-050-250-TPSP-P 50 .250 Tin Plated Copper SPC PTFE

 

 

 

 

semi-rigid-coax-transformer

Other Impedance Coax – Other impedance semi-rigids are commonly used to make baluns or transformers for high power applications, such as in an RF power amplifier.  They are also used to feed antenna structures whose characteristic impedance may not be 50 Ohms.  The broadcast industry widely uses 75 ohm transmission lines for routing signals, so P1dB has a few 75 coax designs from which to choose.

Part Number Impedance (Ω) Diameter (in.) Outer Conductor Center Conductor Dielectric
P1CB-010-034-CUSP-F 10 .034 Bare Copper SPC FEP
P1CB-010-043-SPSP-F 10 .043 Silver Plated Copper SPC FEP
P1CB-010-070-CUSP-F 10 .070 Bare Copper SPC FEP
P1CB-010-070-SPSP-F 10 .070 Silver Plated Copper SPC FEP
P1CB-017-034-CUSP-P 17 .034 Bare Copper SPC PTFE
P1CB-025-034-CUSW-P 25 .034 Bare Copper SPCW PTFE
P1CB-025-070-CUSP-F 25 .070 Bare Copper SPC FEP
P1CB-025-070-SPSP-F 25 .070 Silver Plated Copper SPC FEP
P1CB-025-070-TPSP-F 25 .070 Tin Plated Copper SPC FEP
P1CB-025-090-CUSP-P 25 .090 Bare Copper SPC PTFE
P1CB-025-125-CUSP-P 25 .125 Bare Copper SPC PTFE
P1CB-075-085-CUSW-P 75 .085 Bare Copper SPCW PTFE
P1CB-075-090-CUSP-F 75 .090 Bare Copper SPC FEP
P1CB-075-141-CUSW-P 75 .141 Bare Copper SPCW PTFE
P1CB-093-130-CUSW-P 93 .130 Bare Copper SPCW PTFE

Comments are closed, but trackbacks and pingbacks are open.