Power must often be distributed at different levels within a system. A line of unequal power dividers from R&D Microwaves LLC (www.rdmicrowaves.com) can handle the task for many wireless systems at frequencies from 380 to 2700 MHz. Based on a patented airline structure, the dividers offer power split ratios ranging from as modest at 1:3 (a 6-dB drop in output level relative to input level) to 1:1000 (a 30-dB drop at the coupled port relative to the input level). The unequal power dividers are designed for large-signal applications and feature low passive-intermodulation (PIM) distortion for those systems requiring extremely good linearity performance.

These power dividers (see figure) essentially provide two output ports, one coupled and one approximating a "through" port (although the power appearing at this port will be minus the coupled power along with a small amount of power lost through insertion loss). In some ways, these components can be thought of as couplers with an extra through path. For a divider with a 1:3 split ratio, for example, the nominal insertion loss for the through path is a mere 1.3 dB. The loss at the coupled port is the expected 6 dB, with coupling variations (flatness) held to ±0.5 dB over the full frequency range. The VSWR at input or coupled port is less than 1.45:1 (return loss of better than 14.7 dB).

For a divider at the other extreme, with a 1000:1 split ratio (30-dB coupled port), the through-path insertion loss is a negligible 0.01 dB wile the insertion loss at the coupled port is the expected 30 dB, with coupling flatness of ±1.0 dB over the full frequency range. In both coupling (6 and 30 dB) cases, dissipative losses are only 0.17 dB at 2700 MHz. The VSWR at input or coupled port is less than 1.20:1 (return loss of better than 20.8 dB)

The unequal power-divider models are available with Type N or EIA 7/16 connectors. Split ratios include 1:3, 1:4, 1:5.3, 1:7, 1:10, 1:20, 1:30, 1:100, and 1:1000. The components are designed to handle 300 W average power and 3 kW peak power. The measured PIM is less than –150 dBc.

The rugged unequal power dividers are supplied in passivated aluminum housings with silver-plated brass connectors. The dividers are manufactured without solder joints, but with O-ring seals and flange-mount connectors to achieve an IP65 environmental rating.

The dividers measure 6.23X 1 X 1 in. with EIA 7/16 connectors and 5.71 X 1 X 1 in. with Type N connectors.

In addition to the power dividers, the firm also offers the model C2-A08 dual directional coupler for 824 to 2170 MHz. The patent-pending two-section airline (slabline) design provides 30 dB coupling, with coupling flatness within ±0.4 dB through 960 MHz and within ±0.3 dB from 960 to 2170 MHz. Directivity is typically 30 dB through 960 MHz and typically 25 dB from 960 to 2170 MHz. The dual directional coupler, which can be supplied with Type N or SMA connectors, features RF power ratings to 500 W CW and 2.5 kW peak power. The insertion loss is less than 0.15 dB, with return loss of better than 23 dB. The coupler measures 6.25 1.50 1.50 in.

R&D Microwaves LLC, 11 Melanie Lane, Suite 12, East Hanover, NJ 07936; (908) 212-1696, FAX: (908) 212-7880, Internet: www.rdmicrowaves.com