An apparatus for implementing digital loopback for a radio frequency, RF, system, the apparatus comprising: a receiver, comprising an analog-to-digital converter, ADC, and a first receive, RX, processing unit; a transmitter, comprising a digital-to-analog, DAC, and a first transmit, TX, processing unit; a first digital loopback circuit, comprising a first loopback path, a first combiner, and a first TX weighting circuit, wherein: the first loopback path is configured to provide a signal indicative of an output of the ADC to the first combiner, the first TX weighting circuit is configured to apply a first TX weight to an output of the first TX processing unit to generate a weighted output of the first TX processing unit, and the first combiner is configured to combine a first RX signal and a first TX signal to generate a first combined signal to be provided to the DAC, where the first RX signal is a signal indicative of the output of the ADC, and the first TX signal is a signal indicative of the weighted output of the first TX processing unit; and a second digital loopback circuit, comprising a second loopback path, a second combiner, and a second TX weighting circuit, wherein: the second loopback path is configured to provide a signal indicative of an output of the first RX processing unit to the second combiner, the second TX weighting circuit is configured to apply a second TX weight to a signal indicative of an input digital signal to generate a weighted input for the first TX processing unit, the second combiner is configured to combine a second RX signal and a second TX signal to generate a second combined signal to be provided to the first TX processing unit, where the second RX signal is a signal indicative of the output of the first RX processing unit and the second TX signal is a signal indicative of the weighted input for the first TX processing unit, and the first TX processing unit is configured to generate the output of the first TX processing unit based on the second combined signal. a receiver, comprising an analog-to-digital converter, ADC, and a first receive, RX, processing unit; a transmitter, comprising a digital-to-analog, DAC, and a first transmit, TX, processing unit; a first digital loopback circuit, comprising a first loopback path, a first combiner, and a first TX weighting circuit, wherein: the first loopback path is configured to provide a signal indicative of an output of the ADC to the first combiner, the first TX weighting circuit is configured to apply a first TX weight to an output of the first TX processing unit to generate a weighted output of the first TX processing unit, and the first combiner is configured to combine a first RX signal and a first TX signal to generate a first combined signal to be provided to the DAC, where the first RX signal is a signal indicative of the output of the ADC, and the first TX signal is a signal indicative of the weighted output of the first TX processing unit; and the first loopback path is configured to provide a signal indicative of an output of the ADC to the first combiner, the first TX weighting circuit is configured to apply a first TX weight to an output of the first TX processing unit to generate a weighted output of the first TX processing unit, and the first combiner is configured to combine a first RX signal and a first TX signal to generate a first combined signal to be provided to the DAC, where the first RX signal is a signal indicative of the output of the ADC, and the first TX signal is a signal indicative of the weighted output of the first TX processing unit; and a second digital loopback circuit, comprising a second loopback path, a second combiner, and a second TX weighting circuit, wherein: the second loopback path is configured to provide a signal indicative of an output of the first RX processing unit to the second combiner, the second TX weighting circuit is configured to apply a second TX weight to a signal indicative of an input digital signal to generate a weighted input for the first TX processing unit, the second combiner is configured to combine a second RX signal and a second TX signal to generate a second combined signal to be provided to the first TX processing unit, where the second RX signal is a signal indicative of the output of the first RX processing unit and the second TX signal is a signal indicative of the weighted input for the first TX processing unit, and the first TX processing unit is configured to generate the output of the first TX processing unit based on the second combined signal. the second loopback path is configured to provide a signal indicative of an output of the first RX processing unit to the second combiner, the second TX weighting circuit is configured to apply a second TX weight to a signal indicative of an input digital signal to generate a weighted input for the first TX processing unit, the second combiner is configured to combine a second RX signal and a second TX signal to generate a second combined signal to be provided to the first TX processing unit, where the second RX signal is a signal indicative of the output of the first RX processing unit and the second TX signal is a signal indicative of the weighted input for the first TX processing unit, and the first TX processing unit is configured to generate the output of the first TX processing unit based on the second combined signal.