Do I need a receiver channel when I using ULA?

I'm setting a FMCW radar simulation platform with ULA.

I read example code in helperFMCWTwoRaySimulate.m and Automotive Adaptive Cruise Control Using FMCW Technology.

for m = 1:Nsweep

    % Update radar and target positions
    [radar_pos,radar_vel] = radarmotion(sweeptime);
    [tgt_pos,tgt_vel] = carmotion(sweeptime);

    % Transmit FMCW waveform
    sig = waveform();
    txsig = transmitter(sig);

    % Propagate the signal and reflect off the target
    txsig = txchannel(txsig,radar_pos,tgt_pos,radar_vel,tgt_vel);               % propagate the signal
    rxsig = cartarget(txsig);
    rxsig = rxchannel(rxsig,radar_pos,tgt_pos,radar_vel,tgt_vel);               % propagate the signal
    
    % Dechirp the received radar return
    rxsig = receiver(rxsig);
    xd = dechirp(rxsig,sig);
    xr_unmixed(:,m) = rxsig;
    xr(:,m) = xd;    
end

In % Propagate the signal and reflect off the target, it used two channels for RX and TX respectively

I noticed that if I set a ULA, I don't have to use a reciver channel after collector. Is that right?

    for m = 1:Nsweep
        % Update radar and target positions
        [radar_pos,radar_vel] = radarmotion(waveform.SweepTime);
        [tgt_pos,tgt_vel] = carmotion(waveform.SweepTime);

        % Transmit FMCW waveform
        sig = waveform();
        txsig = transmitter(sig);

        % Radiate the pulse toward the target
        txsig = radiator(txsig,tgtang);

        % Propagate the signal and reflect off the target
        txsig = channel(txsig,radar_pos,tgt_pos,radar_vel,tgt_vel);
        rxsig = cartarget(txsig);
    %   txsig = channel(txsig,tgt_pos,radar_pos,tgt_vel,radar_vel);

        % Collect the echo from the incident angle at the antenna
        rxsig = collector(rxsig,tgtang);

        % Dechirp the received radar return
        rxsig = receiver(rxsig);
        dechirpsig = dechirp(rxsig,sig);

        xr(:,:,m) = dechirpsig;
    end

Answer 1

[Honglei Chen]

The receiver also models the thermal noise in the receiver. If you need to include that effect, then you should not skip the receiver.

HTH

[Wei-Min Chen]

Thanks for your answer !

I just read the documents. It's a problem about one-way propagation or two-way propagation.