How to perform dechirping of SAR image in MATLAB?
Dechirping is a bit different than matched filtering, but perhaps that not important here.

The code you have looks like it should work if the variables are as you describe. Here is a hypothetical example that range compresses an LFM pulse. The reflected signal from an actual target in the scene is a just a delayed version of the waveform, so it will just be a shifted version of what you get when you range compress the transmitted pulse itself:

Tp = 10e-6;              % Pulse length (s)
Brf = 200e6;             % Bandwidth (Hz)
fs = 1.2 * Brf;          % Sampling frequency (Hz)
Ns = ceil( Tp * fs );    % Number of samples per pulse

% Vector of time samples (s)
t = 1/fs * ( -Ns/2 : Ns/2 - 1 ).';

% The LFM waveform.
lfm = exp( 1j * pi * Brf / Tp * t.^2 );

% Matched filter the pulse.
rngcomp = conv2( flipud( conj( lfm ) ), 1, lfm );

% Display the magnitude of the IPR.
plot( 20*log10( abs( rngcomp ) ) );