a.desouki
Newbie level 1
A dual-band receiver employing a Weaver architecture is shown below. The first LO frequency is chosen
so as to create high-side injection for the 2.4GHz band and low-side injection for the 5.2GHz band. (the
receiver operates only in one band at a time). Neglect the noise and non-linearity of the receiver itself and
assume a SNR of 20dB is required for the signal to be detected properly. The Weaver architecture provides
an image rejection ratio of 45dB.
1. Suppose the receiver must detect a -85dBm signal in the 2.4GHz mode while receiving at the same
antenna -10dBm 5.2GHz component as well (interferer). Determine the amount of rejection required
byBPF1 at 5.2GHz.
2. Suppose the receiver operates in the 5.2GHz band but it also picks up a strong component at 7.2GHz.
It is possible for this component to be mixed with the third harmonics ofLO1 andLO2 and appear in
the baseband. Does the Weaver architecture prohibit this phenomenon? Explain in detail.
so as to create high-side injection for the 2.4GHz band and low-side injection for the 5.2GHz band. (the
receiver operates only in one band at a time). Neglect the noise and non-linearity of the receiver itself and
assume a SNR of 20dB is required for the signal to be detected properly. The Weaver architecture provides
an image rejection ratio of 45dB.
1. Suppose the receiver must detect a -85dBm signal in the 2.4GHz mode while receiving at the same
antenna -10dBm 5.2GHz component as well (interferer). Determine the amount of rejection required
byBPF1 at 5.2GHz.
2. Suppose the receiver operates in the 5.2GHz band but it also picks up a strong component at 7.2GHz.
It is possible for this component to be mixed with the third harmonics ofLO1 andLO2 and appear in
the baseband. Does the Weaver architecture prohibit this phenomenon? Explain in detail.