Condition: Used

This listing comprises a matched pair of Marki Microwave CX0421 directional couplers (serial numbers 1810-085 and 1810-086), each rated -13 dB coupling across 1–50 GHz with 2.4 mm RF connectors and an isolated port (ISOL/P42). Both units show signs of use including light surface wear and minor label scuffing consistent with laboratory service.

Included in the sale:
• 2 × Marki Microwave CX0421 directional coupler units (S/N 1810-085 and 1810-086)
• Protective port caps fitted to most connectors (mixed pink/clear and red caps as pictured)

Please note that we have multiple units in stock, and the images presented are of one of them, therefore the cosmetic condition of the exact item you will receive may slightly differ.

The Marki Microwave CX0421 is a matched pair microwave directional coupler designed for ultra-broadband operation from 1 to 50 GHz with a nominal coupling factor of 13 dB. The unit features 2.4 mm coaxial connectors and is constructed using Marki's multisection tri-plate stripline technology, which delivers excellent coupling flatness and low VSWR at all ports across the full operating bandwidth.

Marki Microwave directional couplers allow power to be sampled from a transmission line with selectivity in one direction, discriminating between forward and backward signals. The CX0421 matched pair provides two factory-correlated units for applications requiring symmetric or reference-channel power monitoring, such as VNA reference paths, load-pull test systems, and signal monitoring in advanced microwave test benches.

Marki couplers are characterised by high directivity, excellent coupling flatness, and low VSWR and insertion loss — key parameters for accurate forward and reflected power measurements.

Key Specifications:
Part Number: CX0421
Product Type: Matched Pair Directional Coupler
Frequency Range: 1 – 50 GHz
Coupling Factor: 13 dB
Connector Type: 2.4 mm (female)
Ports: IN, OUT, ISOL (Isolated), Coupled
Construction: Multisection tri-plate stripline
RoHS Compliant: Yes (EU 2011/65/EU, 2015/863)
ECCN: EAR99
Supplier Cage Code: 0UC32

Typical Applications:
- VNA reference channel and signal monitoring
- Load-pull testing and output power sampling
- Broadband power measurement systems
- Forward and reflected power monitoring in microwave systems
- 5G mmWave and satellite communications test infrastructure

For full performance data including coupling flatness, directivity, and insertion loss plots, please refer to the manufacturer's product page at www.markimicrowave.com.