A half-bandwidth based quadrature analog-to-digital converter (ADC) includes in-phase circuitry, quadrature-phase circuitry, and digital complex processing circuitry. The in-phase circuitry includes an in-phase pair of ADCs, which provide an in-phase pair of sub-quadrature output signals, based on an analog in-phase input signal. Similarly, the quadrature-phase circuitry includes a quadrature-phase pair of ADCs, which provide a quadrature-phase pair of sub-quadrature output signals based on an analog quadrature-phase input signal. The digital complex processing circuitry combines, filters, and restructures the in-phase pair of sub-quadrature output signals and the quadrature-phase pair of sub-quadrature output signals to provide a digital in-phase output signal and a digital quadrature-phase output signal. Each of the in-phase pair of ADCs has about an ADC bandwidth. The in-phase circuitry has an input bandwidth, which is about equal to two times the ADC bandwidth in one embodiment of the in-phase circuitry.