A transmission line is provided with a fixed physical length and a programmable electrical length for achieving a programmable time delay. The transmission line can include a dielectric and a biasing device disposed across the dielectric, and the biasing device can dynamically and continuously vary an absolute level of a bias voltage across the dielectric to vary a dielectric constant of the dielectric, which can vary a time delay of the transmission line. In some embodiments, the biasing device can modulate the bias voltage from a positive voltage to a negative voltage at a frequency and with waveform characteristics that prevent such modulation from interfering with a signal propagating through the dielectric, that prevent the bias voltage from unintentionally varying the time delay of the transmission line when the absolute level of the bias voltage is constant, and that prevents ion impurities within the dielectric from accumulating on bias electrodes.