An apparatus of a power amplifier is provided. The apparatus includes an input boosting circuit configured to match a second harmonic input signal using a harmonic control circuit of an input stage to maximize an efficiency and an output power, a die cell configured to receive and amplify an output signal of the input boosting circuit, and an output boosting circuit configured to receive an output signal of the die cell and to match a second harmonic output signal of the output signal of the die cell using a harmonic control circuit of an output stage to maximize the efficiency and the output power.

Apparatus and method for matching harmonics

A bias circuit operable to supply a bias current to a first transistor includes: a second transistor having a collector terminal connected to a first power supply; a first resistance element having one end connected to an emitter terminal of the second transistor and having the other end connected to a base terminal of the first transistor; a second resistance element having one end connected to the emitter terminal of the second transistor and having the other end connected to ground potential; at least one third resistance element provided between a base terminal of the second transistor and a second power supply; and a plurality of temperature compensation circuits connected to the base terminal of the second transistor which are operable to control a base potential of the second transistor so that the potential falls as a temperature rises.

Radio frequency power amplifier

Apparatus and methods for oscillation suppression are disclosed. In one embodiment, a power amplifier system includes a plurality of power amplifiers for amplifying an input radio frequency (RF) signal to generate an output RF signal. The plurality of power amplifiers include a first power amplifier, a second power amplifier, and a third power amplifier, each of which are configured to be individually switchable between an enabled state and a disabled state so as to control a power amplification of the power amplifier system. A first capacitor is electrically connected between the outputs of the first and second power amplifiers, and a second capacitor is electrically connected between the outputs of the second and third power amplifiers. The first and second capacitors are configured to allow signals generated using the first, second, and third power amplifiers to combine constructively to generate the output RF signal.

Apparatus and methods for oscillation suppression

Techniques for efficiently generating a power supply are described In one design, an apparatus includes an envelope amplifier and a boost converter The boost converter generates a boosted supply voltage having a higher voltage than a first supply voltage (eg, a battery voltage) The envelope amplifier generates a second supply voltage based on an envelope signal and the boosted supply voltage (and also possibly the first supply voltage) A power amplifier operates based on the second supply voltage In another design, an apparatus includes a switcher, an envelope amplifier, and a power amplifier The switcher receives a first supply voltage and provides a first supply current The envelope amplifier provides a second supply current based on an envelope signal The power amplifier receives a total supply current including the first and second supply currents In one design, the switcher detects the second supply current and adds an offset to generate a larger first supply current than without the offset

Low-voltage power-efficient envelope tracker

The ever-increasing data rate and number of connections for mobile communication offer exciting user experiences in our everyday lives. Currently, the wireless communication frontier is shifting from the current fourth generation (4G) to the forthcoming fifth generation (5G). We expect much of society to go through a revolutionary change with the advent of the 5G era-a change that will involve not only the telecommunication industry but also a wide range of vertical sectors, including automobiles, robotics, health care, factory automation, agriculture, and education.

A GaN PA for 4G LTE-Advanced and 5G: Meeting the Telecommunication Needs of Various Vertical Sectors Including Automobiles, Robotics, Health Care, Factory Automation, Agriculture, Education, and More

A configuration is provided with: a tuned line 13 that is connected between a branch terminal 3 and a branch terminal of branch lines 2 and 4; and a tuned line 14 that is connected between a combining terminal 7 and a combining terminal 9 of combining lines 10 and 11. This enables reduction of a non-uniform voltage distribution occurring due to a difference in characteristics between two amplifier elements 6 and 8.

High-frequency power amplifier

In this paper, internally matched GaN-HEMT high power amplifiers operating at X- and Ku-bands are presented. For the X-band amplifier, small package is adopted to reduce the over all RF module size. For the Ku-band amplifier, 4 transistor power bars are combined to obtain 100W output power. To the best of our knowledge, this is the first report that more than 100W output power is obtained from single solid state device in Ku-band.

X- and Ku-band internally matched GaN amplifiers with more than 100W output power

Two kinds of high efficiency power amplifiers (PAs) at X and Ku bands utilizing 0.15 μm GaN HEMT technology are presented. The 0.15 μm GaN HEMT technology with cutoff frequency of over 40 GHz enables them to realize high RF performances at higher frequency. To provide better efficiency of the PAs, the second harmonic reflection circuits are employed at both input and output of GaN HEMT chips. The measured results show the X-band GaN HEMT PA achieved power added efficiency (PAE) of 58.6% and output power (P out ) of 30W, and the Ku-band GaN HEMT PA obtained PAE of 33% and P out of 100W under CW operation. To the best of our knowledge, the both PAE of the X-band PA and P out under CW operation of the Ku-band PA are state-of-the-art.

60% PAE, 30W X-band and 33% PAE, 100W Ku-band PAs utilizing 0.15 μm GaN HEMT technology

This study describes the Ku -band 70- and 30-W-class internally matched gallium nitride (GaN) power amplifiers (PAs) for multi-carrier satellite communications (SatComs). The GaN PAs maintain low third-order intermodulation distortion (IMD3) over a wide offset frequency range of up to 400 MHz, whereas in the Ku -band, one PA can deliver a high peak output power of approximately 70 W and the other PA, a peak output power of higher than 30 W. To realize a wide offset frequency operation, our proposed output-matching circuit includes three different types of difference-frequency short circuits, two of which are embedded into a tournament-shaped output-matching circuit inside the PA package and the rest is embedded into the drain bias feed placed outside the package. To verify the short-circuit design and its effectiveness, two different power classes (70 and 30 W), Ku -band GaN PAs, were designed and fabricated, and then, their output transfer characteristics focusing on IMD3 were measured. The measurements show that the 70-W-class GaN PA achieves a peak output power of 48.6 dBm while maintaining a linear output power of over 40 dBm and an IMD3 of less than −26 dBc over wide offset frequencies ranging from 1 to 400 MHz. The 30-W-class GaN PA maintains a linear output power of over 36.3 dBm and an IMD3 of less than −27 dBc over wide offset frequencies of up to approximately 600 MHz. To the best of the authors’ knowledge, these PAs have a record output power level over a wide frequency range of 1–400 MHz or higher under the condition of a low IMD3 of less than −25 dBc, compared to previously reported Ku -band GaN PAs used for multi-carrier SatComs.

Ku -Band 70-/30-W-Class Internally Matched GaN Power Amplifiers With Low IMD3 Over a Wide Offset Frequency Range of Up To 400 MHz

A field-effect transistor with protection diodes includes: a field-effect transistor; and a two-terminal electrostatic protection circuit connected between a gate and a source of the field-effect transistor, wherein the two-terminal electrostatic protection circuit comprises: a first diode that is positioned on a reverse-biased side when a voltage lower than a potential of the source is applied to the gate and has a reverse withstand voltage lower than a reverse withstand voltage between the gate and the source of the field-effect transistor; a second diode that is positioned on a forward-biased side when a voltage lower than a potential of the source is applied to the gate and is connected in anti-series to the first diode; and a resistor that is connected in series to a diode pair comprising the first diode and the second diode and formed using a same channel layer as that of the field-effect transistor.

Maehara Hiroaki

Papers

High-frequency power amplifier

X- and Ku-band internally matched GaN amplifiers with more than 100W output power

60% PAE, 30W X-band and 33% PAE, 100W Ku-band PAs utilizing 0.15 μm GaN HEMT technology

Ku -Band 70-/30-W-Class Internally Matched GaN Power Amplifiers With Low IMD3 Over a Wide Offset Frequency Range of Up To 400 MHz

Field-effect transistor with protection diodes