The Dow-Key Microwave 401U-4208 is a latching electromechanical SPDT coaxial switch engineered for RF and microwave signal routing across DC to 18 GHz. Built with SMA female connectors and a bidirectional RF path, this Break Before Make switch delivers high isolation and low insertion loss across its frequency range. TTL-compatible control input and 12 VDC actuation make it suitable for automated test equipment, radar systems, communication infrastructure, and electronic warfare platforms requiring fast, reliable switching with minimal signal degradation.
## Technical Specifications
• **Frequency Range:** DC to 18 GHz
• **Impedance:** 50 Ohm
• **Connectors:** SMA Female
• **Control Input:** Latching Self Cutoff, TTL Compatible
• **Coil Voltage:** 12 VDC nominal (11–14 VDC operating range)
• **Coil Current:** 230 mA typical at 12 VDC, 25°C
• **Switching Time:** 15 ms maximum
• **Mechanical Life:** 5,000,000 cycles minimum
• **Operating Temperature:** −25°C to +65°C (Extended −55°C to +85°C with “T” option)
• **Weight:** Approximately 2.5 oz (71 g)
• **Vibration:** 10 G RMS, 20–2000 Hz (operating)
• **Shock:** 50 G, 1/2 sine, 11 ms (non-operating)
## Key Features
• **RF Power Handling:** 100 W CW at 0–1 GHz, 50 W at 1–4 GHz, 35 W at 4–8 GHz, 25 W at 8–12 GHz, 10 W at 12–18 GHz
• **Insertion Loss:** 0.10 dB max (0–1 GHz) to 0.50 dB max (12–18 GHz)
• **Isolation:** 85 dB min (0–1 GHz) to 60 dB min (12–18 GHz)
• **VSWR:** 1.10:1 max (0–1 GHz) to 1.50:1 max (12–18 GHz)
• Break Before Make RF switching prevents signal glitches during transitions
• Bidirectional RF path supports flexible signal routing topologies
## Typical Applications
• Automated test equipment (ATE) and signal routing matrices
• Radar system RF front-end switching
• Electronic warfare signal distribution
• Aerospace and defense communication networks
• Lab and production test measurement systems
## Compatibility & Integration
SMA female connectors enable direct integration into 50 Ohm RF systems. TTL-compatible latching control reduces drive circuit complexity. Standard operating range −25°C to +65°C suits most indoor installations; extended temperature option available.
