High-power capability in a passive component requires an understanding of the thermal conductivity of high-frequency circuit materials as well as insight into board layouts that will minimize heat buildup. These guidelines have served the engineers at Innovative Power Products (Holbrook, NY) well in the development high-power couplers, combiners, and terminations for applications from high frequency (HF) through 6 GHz.
The company's focus is on passive components that can literally "take the heat" in that they are rated for high power levels, although the design strategy for all components is to minimize insertion loss and thus minimize dissipation of heat. For example, model IPP-2013 (Fig. 1) is a 3-dB 90-deg. hybrid coupler that operates from 500 to 2500 MHz and handles 200 W average power. Minimum isolation between ports is 18 dB while maximum insertion loss is 0.5 dB. The hybrid coupler, with maximum VSWR of 1.30:1, achieves worst-case amplitude imbalance between ports of ±0.65 dB and worst-case phase imbalance of ±4 deg. The unit measures 2.20X 0.80X 0.20 in. excluding the solder tab connections.
Model IPP-2055 (Fig. 2) is a 3-dB 90-deg. coupler that combines two signals totaling 150 W from 2 to 6 GHz. The 3-dB hybrid coupler features insertion loss of less than 0.45 dB with better than 19 dB port-to-port isolation across the full frequency range. The amount of amplitude imbalance between arms of the hybrid coupler is ±1 dB or less while the amount of phase imbalance is ±5 deg. The hybrid coupler measures 1.30 X 0.25 X 0.13 in. with solder tab connections.
For those needing a directional coupler, the company offers models in bands from 20 to 3000 MHz. The highest-power member of the group is the 50-dB model IPP-3001, with the capability of handling 1000 W average power from 20 to 500 MHz. The rated coupling is flat within ±1 dB. Directivity is better than 20 dB while insertion loss is 0.3 dB or less. The directional coupler measures 6.0 X 2.5 X 1.09 in. excluding Type N connectors.
Model IPP-1000 is an example of the firm's in-phase power-combiner capability. It combines four inputs totaling 750 W average power by merit of maximum insertion loss of 0.4 dB from 400 to 1000 MHz. The maximum VSWR is 1.30:1 while the minimum isolation is 16 dB, leveraging the company's expertise in high-power resistors. The combiner maintains good port-to-port balance, with amplitude imbalance of ±0.2 dB or better and phase imbalance of ±5 deg. or better. It measures 8.52 X 3.27 X 1.37 in. excluding TNC connectors on the signal ports and an SC connector on the output port. In addition to the standard product lines, the firm offers custom resistors, terminations, combiners, and couplers upon request