Abstract: A radio frequency (RF) transmitter includes a transmitter processing module that generates a phase signal that is phase modulated based on outbound data and that generates a amplitude signal that is amplitude modulated based on the outbound data, wherein the amplitude signal is generated in accordance with an amplitude transition rule that restricts an amplitude transition between consecutive amplitudes of the amplitude signal. An up-conversion module phase modulates an oscillation based on the phase signal to generate an up-converted signal. A radio transmitter front-end includes a polar amplifier that amplifies and amplitude modulates the up-converted signal based on the amplitude signal to generate a transmit signal.

Abstract: Low flicker noise mixer and buffer. This design employs some native metal oxide semiconductor field-effect transistors (MOSFETs) (e.g., having no threshold voltage) within a passive mixer whose gates are driven using clock signals. These native MOSFETs maybe biased at one half of the power supply voltage to provide a lower noise figure. A cooperatively operating buffer employs appropriately places MOSFETs and resistors to ensure the desired gain. Relatively larger valued resistors can be employed to provide for higher voltage gain, and this can sometimes be accompanied with using a higher than typical power supply voltage. Source followers serve as output buffers and also ensure the required output DC voltage level as well. It is also noted that this design can be implemented using n-channel metal oxide semiconductor field-effect transistors (N-MOSFETs) of p-channel metal oxide semiconductor field-effect transistors (P-MOSFETs).

Abstract: A method and apparatus provides for, as a part of call setup and routing whenever a calling party calls a called party, which includes determining a local time for the called party prior to completing call setup. If the local time is within a specified time range, a message is played to the calling party to advise the calling party of the local time for the called party. In one embodiment of the invention, the calling party is given the option of leaving a message or of continuing with the call in the case of an emergency. The message delivered to the calling party may be one that is generated by an interactive voice response unit or by a short message service server. In either case, based upon the calling party's response to the message, the inventive method and apparatus result in the cellular network either taking a message for the called party or routing the call to the called party as normal.