We are in the process of designing a radar receiver with a fixed center frequency of about 10.5 GHz and and bandwidth of 50 MHz. It is a cost conscious design based on COTS components.
Following the LNA (e.g. ADL5723) is usually a bandpass filter (BPF) and then the mixer (HMC220B). Can we make the receiver work with a BPF after the mixer and skip the BPF before the mixer?
The reason is that a BPF in the 10 GHz range is expensive (100+ USD) and not easily available, where a BPF with a center frequency of 2.45 GHz or in the lower 1-2 GHz range is readily available from multiple sources at around 1 USD.
Is this a feasible approach?