Imbalance detection and reduction for wideband balun

摘要

A circuit converts a single-ended signal to differential signals that are balanced to have the same amplitudes and opposite phases relative to a reference point of the differential signals. The circuit includes a balance tunable balun, a detector, and a controller. The balance tunable balun has a primary winding, a secondary winding, a control input, and a switched resistor-capacitor (RC) network. The primary winding receives the single-ended signal and the secondary winding outputs the differential signals. The control input receives a control signal and the switched RC network controls the reference point of the differential signals responsive to this control signal. The detector detects the output imbalance and the controller generates the control signal to control the switched RC network to effectively adjust the reference point as needed to reduce that output imbalance. The circuit produces well balanced differential signals over a wide range of signal frequencies.

主权项

1. A circuit configured to convert a single-ended signal to differential signals that are balanced to have the same amplitudes and opposite phases relative to a reference point of the differential signals, the circuit comprising:
a balance tunable balun comprising:
a primary winding configured to receive the single-ended signal;a secondary winding configured to output the differential signals;a control input configured to receive a control signal;a switched resistor-capacitor (RC) network configured to effectively control the reference point of the differential signals responsive to the control signal; a detector configured to detect an output imbalance of the balance tunable balun, the output imbalance comprising an imbalance between the differential signals; and a controller configured to generate the control signal to control the switched RC network to effectively adjust the reference point of the differential signals as needed to reduce the output imbalance detected by the detector.