In digital satellite communication systems, the high power amplifier (HPA) in the satellite repeater and earth station should operate in the vicinity of the saturation point, in order to effectively use output power. Recently, the adoption of constant envelope modulation schemes, like minimum-shift-keying (MSK) and MSK-type modulation (i.e. modified MSK), have been considered to avoid nonlinear harmful influence. This paper describes a new MSK-type modulation scheme, called Gaussian filtered and amplitude limited MSK (GLMSK). The idea behind GLMSK is to remove the envelope variations of the filtered MSK at the modulator by using a limiter with a small AM-PM conversion coefficient. GLMSK performance is calculated and estimated on some parameters, and the implemented GLMSK modem operation and performance are shown at a nominal data transmission rate of a 100 Mbit/s and an intermediate frequency of 1.7 GHz. Constant envelope GLMSK with a narrow spectral band can be achieved by using conventional high-speed MSK modem techniques.