Low loss and wide bandwidth are two desirable features in a directional coupler intended for signal-monitoring purposes, and those are two of the strong traits of the new model SYDC-10-42HP+ directional coupler from Mini-Circuits. It is a 10-dB coupler with coupling flat within ±0.3 dB from 10 to 400 MHz. The mainline loss is only 0.3 dB above the 0.45-dB theoretical minimum. The directivity is typically 32 dB at 10 MHz, 18 dB at 250 MHz, and 12 dB at 400 MHz. The input and output return loss is typically 22 dB. The compact directional coupler measures only 0.5 x 0.6 x 0.4 in., but can handle signal levels as high as 16 W without damage.