The complexity of harmonic rejection N-path mixer based receivers is studied in this paper. A solution to improve harmonic rejection without increasing the complexity is presented and compared with conventional LNA-first receivers. This solution is based on π-delayed driving signals that enable a N-path mixer to present the same harmonic rejection than its 2N-path counterparts while reducing by 2 the frequency of operation and showing a reduced number of differential gain stages and switches. A 5-path mixer is thus proposed. It allows rejecting up to the 8 th harmonic with only 3 differential gain stages whereas only the 6 th harmonic would be rejected with conventional topologies having the same number of amplifier stages.