Abstract: An H-bridge circuit formed from two sub-circuits coupled to each other by a load network across a respective load node of each of the sub-circuits. Each sub-circuit of the two sub-circuits comprises a depletion mode upper transistor with a second electrode coupled to a first electrode of a lower transistor. The load node of the sub-circuit is disposed between the second electrode of the upper transistor and the first electrode of a lower transistor. There is a first voltage supply node coupled to a first electrode of the upper transistor and a second voltage supply node is coupled to a second electrode of the lower transistor. An upper driver transistor selectively couples a gate electrode of the upper transistor to an upper drive voltage node, the upper driver transistor having a control electrode coupled to an upper switched voltage supply circuit.

Abstract: A method and apparatus for direct conversion of digital data to high power RF signals, known as DDRF. The method and apparatus receive a digital signal, create a digital modulated signal therefrom, and amplify the modulated signal with an H-bridge Power Amplifier for transmission. DDRF uses a multi-level H-bridge amplification circuit to establish a more power efficient digital transmitter.

Abstract: An H-bridge circuit formed from two sub-circuits coupled to each other by a load network across a respective load node of each of the sub-circuits. Each sub-circuit of the two sub-circuits comprises a depletion mode upper transistor with a second electrode coupled to a first electrode of a lower transistor. The load node of the sub-circuit is disposed between the second electrode of the upper transistor and the first electrode of a lower transistor. There is a first voltage supply node coupled to a first electrode of the upper transistor and a second voltage supply node is coupled to a second electrode of the lower transistor. An upper driver transistor selectively couples a gate electrode of the upper transistor to an upper drive voltage node, the upper driver transistor having a control electrode coupled to an upper switched voltage supply circuit.

Abstract: A method and apparatus for direct conversion of digital data to high power RF signals, known as DDRF. The method and apparatus receive a digital signal, create a digital modulated signal therefrom, and amplify the modulated signal with an H-bridge Power Amplifier for transmission. DDRF uses a multi-level H-bridge amplification circuit to establish a more power efficient digital transmitter.

Abstract: A power amplifier that includes: an input drive controller (310) for receiving an input signal (312) and for generating from the input signal at least a first drive signal (314), a second drive signal (316), and a third drive signal (318); an outphasing amplifier network (320) coupled to the input drive controller that includes at least a first outphasing amplifier (322) for amplifying the first drive signal and a second outphasing amplifier (326) for amplifying the second drive signal; a peaking amplifier network (330) coupled to the input drive controller that includes at least a first peaking amplifier (332) for amplifying the third drive signal; and a combining network (340) coupled to the outphasing amplifier network and the peaking amplifier network for combining at least the amplified first, second and third drive signals to generate an output signal at a load.

Abstract: A multilayer ceramic device (100) includes a plurality of dielectric layers (104A-G) separated by ground planes (114) and includes a plurality transmission line segments (118) in generally folded configuration for defining a tapered transmission line (102). The profile of the transmission line may vary and includes such profiles as embodied in the depicted lines (200, 206, 212).

Abstract: A multilayer ceramic device (100) includes a plurality of dielectric layers (104A-G) separated by ground planes (114) and includes a plurality transmission line segments (118) in generally folded configuration for defining a tapered transmission line (102). The profile of the transmission line may vary and includes such profiles as embodied in the depicted lines (200, 206, 212).

Abstract: An amplifier apparatus for a multimode mobile communication device includes a carrier amplifier (114) and a peaking amplifier (116). The peaking amplifier has an adjustable bias level and is adjusted by a regulator to a predetermined level, depending on which mode of communication is selected. The bias level on the peaking amplifier is held constant so long as the mode of communication is the same. By adjusting the bias point of the peaking amplifier in conjunction with the selection of the mode of communication, the efficiency and the linearity of modulation can be optimized for the particular mode of communication.

Abstract: A power amplifier includes a carrier amplifier path and a peaking amplifier path. The carrier amplifier path includes a carrier amplifier (208), and an impedance transforming network (214). The peaking amplifier path includes a peaking amplifier (210), an impedance transforming network (216), and a phase delay quarter wave element (226). The arrangement forms an inverted Doherty combiner where as the nominal impedance at a summing node (230) increases with increased conduction from the peaking amplifier, the load impedance at the output of the carrier amplifier decreases so as to maintain the carrier amplifier at a saturation point as the input signal (232) increases, and results in a reduction of the number of phase delay elements needed over a conventional Doherty approach. In a preferred embodiment the carrier and peaking amplifiers consist of cascaded stages, and are disposed on a common integrated circuit die (304).

Abstract: An amplifier (300) comprising two amplifier stages (301, 303), a signal splitter (305), and a signal combiner (307) amplifies an amplitude-varying input signal (128) in the following manner. The signal splitter (305) receives a signal of varying amplitude (128) and splits the received signal into a first amplitude-varying signal (325) and a second amplitude-varying signal (327). The first amplifier stage (301) applies a first gain to the first amplitude-varying signal (325). The second amplifier stage (303) applies a second gain that is greater than the first gain to the second amplitude-varying signal (327) only when an amplitude of the second amplitude-varying signal (327) exceeds a threshold. The signal combiner (307) combines the amplified signals outputted from the amplifier stages (301, 303) to produce the amplifier output signal.

Abstract: A high efficiency power amplifier 600 consists of a non-linear radio frequency (RF) Doherty power amplifier (67) and a linearization circuit, such as, for example, a Cartesian Feedback circuit (33), an RF feedback circuit (38), an IF feedback circuit (48), or a feedforward circuit (55). The Doherty amplification stage (67) may be implemented with a BJTs, FETs, HBTs, H-FETs, PHEMTs, or any other type power transistor technology or device.

Abstract: An amplifier structure (200) includes a main amplifier loop (203) for efficiently amplifying an input signal at a power amplifier (228) coupled to a load susceptible to impedance variations. The amplifier structure (200) includes a DC correction circuit (214) for detecting and correcting misadjustments in the amplifier (200) in order to eliminate DC offset associated therewith.

Abstract: An amplifier structure (200) includes a main amplifier loop (203) for efficiently amplifying an input signal at a power amplifier (228) coupled to a load susceptible to impedance variations. The amplifier loop (200) further includes an auxiliary loop (201) coupled to the main loop (201) for simultaneously preventing the power amplifier (228) from operating inefficiently or causing off-channel interference.

Abstract: A linear transmitter (100), which utilizes closed loop feedback to maintain its linearity, employs a method for reducing off-channel interference produced by the linear transmitter (100). A dynamically alterable parameter source (DAPS, 126) is provided to the linear transmitter (100). The DAPS (126) is then used to adjust at least one loop parameter of the closed loop feedback such that off-channel interference is reduced.

Abstract: In a radio transmitter (100) that includes a power amplifier (104) and an antenna (106), a method for enhancing an operating characteristic of the radio transmitter (100) can be accomplished in the following manner. The power amplifier (104) provides a signal (113) to a variable matching network (111), wherein the signal (113) comprises energy to be radiated by the antenna (106). The variable matching network (111) couples the signal (113) to a sampler (112) that is operably coupled to an output of the variable matching network (111 ) and the antenna (106). The sampler (112) samples a forward component (114) and a reflected component (115) of the signal (113). The radio transmitter (100) processes the sampled forward and reflected components (116, 118) to produce a feedback control signal (120). The feedback control signal (120) is used to adjust the variable matching network (111 ), such that an operating characteristic of the radio transmitter (100) is enhanced.

Abstract: A method and apparatus is provided for a transmitter (200) with a stable, linear response. The transmitter (200) includes an amplification stage (242), and a negative feedback correction loop (244) with a feedback signal (252). A reference signal (251) is combined with the feedback signal (252) to produce an error signal (253) for coupling to the amplification stage (242). Transmitter parameters are varied when a difference between the reference signal (251) and the error signal (253) exceeds a particular threshold.

Abstract: A transmitter that includes an amplifying element, an antenna, a gain stage, and a closed loop feedback may compensate for varying antenna loads without an isolator. This may be accomplished by determining the effects of the varying loading on overall loop gain. Knowing the effects, the transmitter adjusts the gain of the gain stage to maintain a constant overall loop gain, thus eliminating the need for an isolator.

Abstract: Power amplifiers, which include a feedback element, may be protected from excessive operating power levels by adjusting the feedback element to reduce the drive signals to the power elements. This is accomplished by sensing the output power of the power amplifier to produce a sensing signal. When the sensing signal exceeds a predetermined threshold, a feedback element is adjusted to produce an increased feedback signal. The increased feedback signal is subtracted from an input signal, thus decreasing the drive signal. With the drive signal reduced, the output power is reduced proportional to the adjustment of the feedback element.

Abstract: A transmitter that includes an amplifying element, an antenna, a gain stage, and a closed loop feedback may compensate for varying antenna loads without an isolator. This may be accomplished by determining the effects of the varying loading on overall loop gain. Knowing the effects, the transmitter adjusts the gain of the gain stage to maintain a constant overall loop gain, thus eliminating the need for an isolator.

Abstract: A broadband RF transformer design is described that facilitates the construction of a broadband impedance transformer in a compact, planar format, while retaining ease of assembly and manufacture. Broadband operation is achieved through the use of a slotted low-impedance winding structure, common-manufacture ferrite elements, and the optional placement of reactive elements between winding turns. By virtue of construction, thermal performance is enhanced, allowing operation at power levels not previously possible. The invention accommodates functional tuning via laser or abrading techniques. Also, the winding configuration eliminates the need to access the center of a spiral for the purposes of establishing a ground connection.