An example apparatus includes a polyphase transconductance-capacitor filter. The polyphase filter includes a DC bias voltage node, a plus in-phase filter unit, a minus in-phase filter unit, a plus quadrature-phase filter unit, and a minus quadrature-phase filter unit. Each filter unit respectively includes an input node, an output node, and a control node. The polyphase filter also includes a plus in-phase switch and a minus in-phase switch. The plus in-phase switch is coupled to the control node of the plus in-phase filter unit, the DC bias voltage node, and the input node of one or both of the plus quadrature-phase filter unit and the minus quadrature-phase filter unit. The minus in-phase switch is coupled to the control node of the minus in-phase filter unit, the DC bias voltage node, and the input node of one or both of the plus quadrature-phase filter unit and the minus quadrature-phase filter unit.