Abstract: A portable communication device (102) includes a housing (105), a first display area (130), and a second display area (132). The first display area (130) is disposed in and outwardly directed from a front (120) of the housing (105), and the second display area (132) is disposed in and outwardly directed from a side (122) of the housing (105). The housing (105) may include a housing portion (114) movable to an open position and a closed position, where the second display area (132) is covered by the housing portion (114) when positioned in one of the first and the second positions.

Abstract: A portable communication device (102) includes a housing (105), a first display area (130), and a second display area (132). The first display area (130) is outwardly directed from a side (122) of the housing (105), and the second display area (132) is outwardly directed from a front (120) of the housing (105). The housing (105) may include a housing portion (114) movable to an open position and a closed position, where the second display area (132) is covered by the housing portion (114) when positioned in one of the first and the second positions.

Abstract: A dual-mode RF signal power amplifier combining network is comprised of two branches, each having a power amplifier (200 and 201). The first branch contains a non-linear mode power amplifier (200) while the second branch contains a linear mode power amplifier (201). The non-linear mode branch also has an RF switch (210). Both branches are coupled to a common output node (220). The common node (220) is coupled to a filter (107) before going to an antenna (106). The non-linear mode power amplifier (200) operates when an FM signal is to be amplified, while the linear amplifier (201) is biased in an off state. The linear mode power amplifier (201) operates when a digital signal is to be amplified, while the non-linear amplifier (200) is biased in an off state. The RF switch (210) removes the non-linear amplifier (200) from the circuit to prevent loading the on state linear amplifier (201).

Abstract: An apparatus and method for varying coupling of a radio frequency (RF) signal (408). This is advantageously used for increasing the dynamic range of a power detector (406) in an automatic power level control loop (403) of a transmission unit (404), while maintaining transmission unit efficiency at higher power levels. This is accomplished by selecting between a first operating mode of the RF coupler (405) having strong coupling, responsive to a first predetermined power level, such that the RF coupler (405) produces a first coupled RF signal (509) responsive to the RF signal (408) and a second operating mode of the RF coupler (405) having weak coupling, responsive to a second predetermined power level, such that the RF coupler (405) produces a second coupled RF signal (510) responsive to the RF signal (408).

Abstract: A transmitter (604) of a TDMA cellular telephone (600) includes power control circuitry (100) comprised of variable gain stage (104), mixer (106), bandpass filter (109), RF amplifier (110), and directional coupler (112) in a forward path, and two detectors (116 and 117), four A/D converters (118, 119, 121 and 123), digital controller (120), and D/A converter (126) in a feedback path. In operation, the variable gain stage (104) is responsive to a gain control signal AOCCNT (128) for adjusting a modulated IF signal, which is then mixed in mixer (106) with an RF reference signal to produce the transmit RF signal. The temperature and supply voltage are sampled by controller (120) at the beginning of each time slot. Adjustments in the gain control signal (128) dictated by the sampled temperature and supply voltage are made by controller (120) in each time slot prior to keying the RF amplifier (110).

Abstract: The dual mode power amplifier apparatus of the present invention is comprised of a number of power amplifiers (101-103) coupled to a voltage convertor (104) through their collector supply lines. A mode select line (105) is connected to the voltage convertor (104) to select a digital or analog mode. The preferred embodiment of the present invention is used in a hybrid digital/analog radiotelephone. In the digital mode, the voltage convertor (104) is turned off and the voltage convertor (104) supply voltage is allowed through to the collectors of the power amplifiers (101-103). This permits the power amplifiers (101-103) to operate with optimum linearity in a digital transmission environment. In an analog environment, the voltage convertor (104) is on and supplying a reduced voltage to the power amplifiers (101-103) allowing more efficient operation in this mode.

Abstract: A cellular telephone transmitter (100) includes a variable-gain power amplifier (102), the output of which is filtered and sampled by a filter (104) with an integral directional coupler. Filter (104) includes both a transmitter signal filter and a directional coupler on a ceramic block of one or more pieces. The directional coupler has been realized by two coupled transmission lines provided by the two holes (206 and 207) on the left side of the ceramic block, and the transmitter filter has been realized by five short-circuited coupled transmission lines provided by the five holes (201-205) on the right side of the ceramic block.

Abstract: A gain control system for controlling signal levels of the signal received by a receiver. The gain control system is operable to control the signal levels of the signal when the signal is comprised of either a conventional, constant envelope signal, such as an FM signal, or a non-constant envelope signal, such as a TDMA composite modulated signal. The gain control system may be advantageously embodied in a dual-mode radiotelephone operable to receive both conventional, FM signals and TDMA, composite modulated signals.

Abstract: A dual mode power amplifier operable in etiher the linear mode or the saturation mode. The power amplifier, when comprising a portion of a radio transmitter, permits efficient amplification of either a frequency modulated or a composite modulated signal by operation of the amplifier in the saturation mode or the linear mode, respectively. A processor determines the modulation-type of the signal and generates a signal to cause operation of the amplifier in either the saturation mode or the linear mode.