A gain enhanced dual-band filtenna operating at frequency bands of 3.5 and 5.3 GHz for 5G sub-6 GHz applications is presented in this article. A dual-band antenna is integrated with a filter to improve selectivity. The antenna uses printed monopoles as the radiating element, and the filtering response is achieved using a modified feedline. The designed filtenna is 50 × 38 × 1.63 mm3 in size with a maximum gain of 2.5 dBi. The novel filtenna design is equipped with an artificial magnetic conductor (AMC) for the first time to enhance the performance. A unit cell for the AMC is designed that offers zero phase shift in the desired frequencies. A four by four AMC array is designed using this unit cell, which is used as a reflective surface to improve the radiation characteristics of the filtenna. The gain of the filtenna is improved three times up to 7.5 dBi in both bands. The proposed design's overall planar dimensions are 80 × 80 mm2. Using AMC, the gain has improved with a very minute or no change in the other characteristics. The measured results are congruent with the simulated ones, illustrating that the filtenna has good impedance matching and excellent gain in both bands.