Abstract: Disclosed herein are compounds of formula I: or a pharmaceutically acceptable salt thereof, where the variables are as defined herein. These compounds are useful in treating RET associated cancers. Formulations containing the compounds of formula I and methods of making the compounds of formula I are also disclosed.

Abstract: An amplification system for amplifying an input signal at radio frequency comprises a linear power amplifier and a drive unit. In a test mode, the drive unit feeds two signal tones simultaneously to the amplifier input and a processing circuit analyse the output of the amplifier to identify distorting IMPs. A predistortion circuit operates in an amplification mode to apply a predistortion to a digital representation of the input signal to compensate for the effect of the distorting IMPs generated in the amplifier.

Abstract: The present invention is a seal for an open end of an end cap which is adapted to be at least partially disposed in a cavity of a member. The seal includes an axial portion adapted to extend axially along an axial flange forming the open end of the end cap. The seal also includes at least one relief extending axially along the axial portion for allowing gaseous fluid to communicate between the cavity of the member and atmosphere.

Abstract: A radio transmitter includes a bank of pre-distortion circuits each of which is selectively connectable between the mixing stages of the transmitter and the final linear power amplifier stage of the transmitter. The pre-distortion circuit to be connected is determined by the RF frequency of the signal to be transmitted. A method of analyzing the distortion produced by a linear power amplifier is also described. In this method two tones are applied to the amplifier and the resulting down-mixed signal is subjected to a FET in order to derive the spectrum and plot the amplitude and phase distortion against the two tone amplitude. Analysis of the results of such testing allows the pre-distortion circuits to be designed to compensate for distortion produced by the amplifier over the complete operating frequency range of the transmitter.