Electromagnetic absorbers are divided into different types such as pyramidal graphite absorbers, magnetic nano ingredients and etc. The pyramidal absorbers used in anechoic chambers have low reflections but they are bulky; as a result, it is impossible to be used in all applications. Moreover, the pyramidal absorbers are usually used in closed environment because of their sensitivity to dust, humidity and temperature. Another type of absorbers are frequency selective surfaces (FSS) to remedy the defections of the aforementioned cases. The main advantages of them are low weight, volume, and cost and also are less sensitivity to environment conditions compared to the traditional graphite absorbers. The FSS absorbers made from lossy elements are used vastly to produce absorbers with lightweight and smooth surfaces. These absorbers consist of a resistive sheet mounted onequarter wavelength in front of a ground plane, named Salisbury screen. These structures can be justify; MARGIN: 0cm 0cm 8pt; unicode-bidi: embed; DIRECTION: ltr" First kind is a resistive sheet structure to form square and cross arrays, or square loops. The resistive sheets can reduce radar cross section (RCS) of objects. The second kind of FSS absorbers is a resistive element structure that includes copper layer and lumped resistors. The first absorbers are usually used as FSS radomes for the RCS reduction of antennas. In another work, multi-layered square FSS is used to reduce RCS of antennas and object scattering. Also, the FSS structures can be used as a ground plane in patch antennas. These resistive sheet structures are often broadband. But the main drawback of them is the need of given value of surface resistance (?/square) which is unavailable and costly.For the second FSS absorbers, the elements for fabrication are available, cheap and easy. However, the design of these absorbers is dependent on the configuration and resistor values such as double square loops or Minkowski loops. In my research, the design of a lossy frequency selective surface absorber consisting of a two-dimensional periodic array of resistor-loaded such as double fractal square loops, double circular loops and star loops are considered at X-band. The printed loops and mounted resistors are placed on the top layer of a FR4 layer which is on a foam substrate with a back-plane ground. The foam thickness is ?/4, where ? is the wavelength at the frequency center of desired bandwidth similar to a Salisbury screen. The single-layer absorbers which are easy to be fabricatedcan give a wide -10dB reflectivity bandwidth even in the lower frequency range. The double-fractal square loop with 8 lumped resistors offers a -10dB reflectivity bandwidth of 125% and good angle stability (±30) respect to the normal incidence. The double circular-loop FSS shows the reflectivity bandwidth of 115% and excellent angle stability even for ±45. The last design, i.e. the star loop FSS, illustrates the reflectivity bandwidth of 107% and excellent angle stability similar to the previous design. Several parameters influence on the significant characteristics of the absorbers such as inner or outer resistors and substrate thickness. In particular, the equivalent circuit model of the frequency characteristics for the normal incidence is presented. Keywords: Radar Cross Section Reduction, Frequency Selective Surfaces, Absorbers, Lumped Resistors.