Spectrum Control Inner/Outer DC Blocks provide DC isolation on both the center and outer conductors of a coaxial transmission line while allowing RF and microwave signals to pass with minimal loss. This provides more complete DC isolation between interconnected RF components.
Available in multiple frequency ranges, voltage ratings, and connector configurations, Inner/Outer DC Blocks support applications requiring isolation of both signal and ground paths. Their passive design makes them well suited for test, communications, aerospace, defense, and other RF and microwave systems.
Inner-Outer DC Block Performance & Selection
How it Works
An Outer DC Block uses a series capacitor on the outer conductor to block DC while allowing RF and microwave signals to pass. The center conductor remains electrically continuous, distinguishing Outer DC Blocks from Inner and Inner/Outer designs.
Understanding DC Block Performance
Outer DC Blocks are designed to isolate DC on the outer conductor while maintaining efficient RF and microwave transmission. When selecting a model, consider these key specifications:
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Operating Frequency: Select a frequency range that supports your application.
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Signal Integrity: Low insertion loss and VSWR help reduce signal loss and reflections.
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Voltage & Interface: Choose the appropriate voltage rating and connector configuration.
With the center conductor remaining continuous, an Outer DC Block isolates unwanted DC on the shield while preserving the RF signal path and system performance.
Why it Matters
Outer DC isolation can help eliminate unwanted DC or audio current on the outer conductor, reduce interference between interconnected equipment, and improve isolation in RF and microwave systems.
Part Number |
Freq. Range (GHz) |
Voltage |
VSWR Max. |
Insertion Loss (dB) |
Connector / Configuration |
| General Purpose | |||||
| 0.1 - 50 | 75 | 1.75:1 | 1.5 | 2.4mm - M/F | |
| 0.01 - 40 | 200 | 1.45:1 | 0.5 | 2.9mm - M/F | |
| 0.01 - 26.5 | 200 | 1.35:1 | 0.5 | 2.9mm - M/F | |
| 0.01 - 18 | 200 | 1.35:1 | 0.6 | N-Type - M/F | |
| 0.01 - 18 | 200 | 1.35:1 | 0.5 | SMA - M/F | |
| 2 - 3 | 100 | 1.15:1 | 0.2 | SMA - Hex - M/F | |
| 0.01 - 18 | 200 | 1.35:1 | 0.5 | SMA - F/F | |
Outer DC Block - How it Works
Blocks DC on the outer conductor while allowing RF signals to pass.
Typical Applications
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RF and microwave test systems
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Radar and sensing equipment
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Electronic warfare platforms
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Satellite and wireless communications
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Avionics and defense systems
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RF system interconnects
- Ground-loop mitigation
- DC isolation for sensitive RF equipment
Why Choose Spectrum Control?
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Wide range of DC block configurations
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RF and microwave coverage through 50 GHz
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Voltage options for diverse system requirements
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Multiple coaxial connector interfaces
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Low-loss designs for signal integrity
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Compact 50-ohm passive solutions
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Flexible connector and mechanical options
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Comprehensive electrical and mechanical specifications