Intermodulation improvement by appropriate channel allocations

Intermodulation interferences of multicarrier signals can be reduced at the expense of increased bandwidth if the signal carriers are arranged in appropriate frequency plans. The paper investigates in detail the trade-off between bandwidth and intermodulation interference. The results are presented in tabular form.     

Phase noise of mixers

A formula is derived for the output phase noise of a mixer when both the radio frequency RF and local oscillator LO carriers are impaired by phase noise. The calculation uses test results obtained with three discrete carriers. An application of the noise formula to frequency synthesis is included.     

Resistive coupler

A directional coupler is described that, unlike conventional couplers, contains lossy elements (resistors). The resulting increase in insertion loss is the tradeoff for the simple design and the broadband capabilities.