  Stealthy electronically reconfigurable transmitarray antennas are essential
components in wireless communication and radar detection systems. Therefore,
this paper proposes a 1 bit electronically reconfigurable transmitarray antenna
with out-of-band scatter suppression. The transmitarray consists of two layers,
the absorptive frequency selective transmission (AFST) layer and reconfigurable
transmitarray (RTA) layer, separated by air. Specifically, the AFST layer
achieves out-of-band scattering suppression and in-band transmission
performance by utilizing the first three resonant modes of a bent metallic
strip with a centrally loaded resistor. Additionally, the RTA layer adopts a
receiver-transmitter structure with an active receiving dipole and a passive
orthogonal transmitting dipole. The 1 bit phase shift is achieved by
alternating two pin diodes integrated on the active dipole to reverse its
current direction. To evaluate the proposed design, a 256-element transmitarray
prototype is designed, fabricated and measured. For scattering, the 10-dB radar
cross section reduction is realized within 4~5.2 GHz and 10.9~11.4 GHz,
respectively. For radiation, the measured gain is 19.9 dBi at 7.5 GHz,
corresponding to an aperture efficiency of 12.1%. and the beam scanning covers
60{\deg} with gain loss of 5 dB in both two principal planes.
