Silicon Dioxide Cable Assembly
Silicon Dioxide cable is a high stability cable at high temperatures and high frequencies. Because of this high stability silicon dioxide cables are currently used in nuclear reactors, decoy boxes, radars, satellites, aircraft and sophisticated missile applications. Measure Tech's Silicon Dioxide cable assemblies are excellent for operation in extreme environment conditions where stability is crucial. Measure Tech's Silicon Dioxide cable is currently used by Lockheed Martin in their JASSM missiles. Measure Tech currently has 100% on time delivery for the Silicon Dioxide Cables delivered to Lockheed Martin.
The Silicon Dioxide Cable assemblies manufactured by Measure Tech are available with a variety of connector choices, diameters, lengths and bends.
- » Specifications tables
- » Insertion Loss vs. Frequency Graph
- » Insertion Loss vs. Temperature Graph
- » Phase Change from Ambient Temperature
Measure Tech's silicon dioxide cable assemblies are excellent for operation in extreme environment conditions where stability is crucial. Our product is currently used by Lockheed Martin in their JASSM missiles.
Benefits
- Excellent phase stability
- Low insertion loss
- Extreme temperature resistance (-270°C to 1000°C)
- Lightweight
- Superior capacitance stability and insulation resistance at high temperatures
Performance
Silicon dioxide cables provide excellent insulation resistance as well as superior phase and capacitance stability at high temperatures and thus are a superior choice for data transmission during rough circumstances. For such extreme environmental conditions where an exceptional signal to noise ratio is desired, silicon dioxide cables' performance is unparalleled.
Fabrication
Measure Tech's unique fabrication process utilizes high purity (99.98%) silicon dioxide powder to reduce the dielectric constant of the insulation from 4.0 to 1.6. As the insulation is manufactured, air is introduced into the insulation where it is later removed and replaced by inert atmosphere. This process provides the low dielectric constant required for these low loss microwave cable assemblies. In addition, this process allows for an environment where oxygen molecules are not present in the cable which prevents oxidization.
The outer jacket of the cable is normally manufactured with a composite material. The inner layer is made of high conductivity OFHC copper while 304L stainless steel is used for the outer layer. The stainless steel outer layer provides resistance to corrosion and is welded to the connectors. For applications where a more flexible cable is required, a fully annealed copper can be used for the outer jacket. A high strength material such as inconel or other alloys also can be used for the outer jacket.
Connectors
For years Measure Tech has been manufacturing glass to metal seals for special applications such as microwave feedthroughs and hermetically sealed microwave connectors. For high temperature applications, ceramic composite glass can be used when temperature exposures are up to 750°C. The unique sealing techniques used at Measure Tech allow for controlled cooling of polycrystalline glass. This process permits fabrication of glass ceramic to metal seals with a high expansion suitable for sealing to nickel base alloys, such as Inconel 625 and Inconel X750, as well as Inconel 718, which can be subject to precipitation hardening.
Technical Data
Figure 1 demonstrates the insertion loss due to temperature at four different frequencies; 4 GHz, 10GHz, 14 Ghz and 18 GHz. For the 18GHz frequency a .061dB/ft or 11.62% insertion loss is achieved.
Figure 1. Insertion Loss due to Frequency
Figure 2. Insertion Loss due to Temperature
Figure 3. Phase Change from Ambient Temperature
| SiO2 Cable Specifications | |
|---|---|
| Design & Performance Specifications | |
| Outside diameter | 0.142 inches |
| Weight | Low, ~ 0.30 lb/ft*** |
| Bend radius | 0.22 inch radius |
| Capacitance | 25 pF/ft |
| Velocity of propogation | 0.8 |
| EMI shielding | Excellent, > 110 dB |
| Delay | 1.25 nanoseconds/ft |
| Cut-off frequency | 40 GHz |
| Hermeticity | 1×10-8 cc/sec helium leak rate |
| Insulation resistance | Ambient: 1×1014 ohm, 750°C: 1×107 ohm |
| Material Specifications | |
| Outer jacket | Series 304L stainless steel |
| Outer conductor | OFHC copper |
| Center conductor | OFHC copper |
| Dielectric | Low density, high purity (99.98%) silicon dioxide |
| Dielectric constant | 1.6 |
| Environmental Specifications | |
| Cable operating temperature | -273°C to 1000°C |
| Connector operating remperature (standard) |
-273°C to 200°C |
| Connector operating temperature (high temperature) |
-273°C to 600°C |
| Chemical resistance | Equivalent to 304L series stainless steel |
| Radiation resistance | Excellent |
Table 1
| Frequency | VSWR |
|---|---|
| 2 GHz to 4 GHz | 1.20:1 |
| 4 GHz to 8 GHz | 1.25:1 |
| 8 GHz to 12 GHz | 1.30:1 |
| 12 GHz to 16 GHz | 1.35:1 |
| 16 GHz to 20 GHz | 1.45:1 |
Table 2