Advanced Order Linearizer for Satellite Communications

LTI has extensive experience producing analog predistortion linearizers for microwave and millimeter-wave bands. Its linearizers are higher order linearizers, based on correcting a PA"s transfer characteristics without cancelling specific order IMD products. LTI designs when integrated with a PA can match the performance of an ideal amplifier. To operate closer to saturation than an ideal amplifier, the peak-to-average characteristics of a signal can be reduced. Limitations of LTI"s linearizers are the need for meticulous tuning to achieve the desired characteristics, and the need for adjustment to match the PA"s specific characteristics. To overcome these limitations, LTI has developed an adaptive analog PDL for Ku-band. This linearizer operates from 13.75 to 14.5 GHz with multicarrier signals and all forms of modulation across its full 750 MHz bandwidth. LTI will produce a prototype Ka-band AAPDL (30-31 GHz) and a preliminary design for a Q-band version. This linearizer will be capable of multicarrier operation over its full instantaneous bandwidth. It will provide across the band and up to saturated power an AM/PM of less than 1 degrees /dB, and an adjacent channel power ratio approaching that of an ideal amplifier.