Can the MAX2830 be operated with zero offset at the input?
Technically, it cannot. There is low-pass filter to attenuate interference in the RX baseband. The chip also includes a programmable high pass filter for DC offset removal. The lowest high-pass corner frequency is 100Hz, not truly DC. But compared to a 20MHz wideband modulated 802.11 signal, 100Hz is close to DC.
