PMI Model No. QC-5D3G6G is a quadrature coupler that operates over the frequency range of 5.3 to 6.0 GHz.  This model provides low loss of 1 dB and an isolation of 18 dB minimum.  The VSWR is 1.4:1 maximum into a 50 ohm impedance.  The amplitude balance is ±0.7 dB maximum and the phase balance is ±5° maximum. 

This model is supplied with SMA male connectors in a housing measuring 1.25" x 0.75" x 0.33".

• Frequency Range: 5.3 to 6.0 GHz
• Insertion Loss: 1.0 dB Max. - Measured 1.0 dB
• Amplitude Balance: ±0.7 dB Max. - Measured ±0.4°
• Phase Balance: ±5.0° Max. - Measured ±2.4°
• Isolation: 18 dB Min. - Measured 19.8 dB
• VSWR: 1.4:1 Max. - Measured 1.28:1
• Impedance: 50 Ohms

http://www.pmi-rf.com/products/couplers/QC-5D3G6G.htm