Abstract: Power amplifier modules (PAMs) having topside cooling interfaces are disclosed, as are methods for fabricating such PAMs. In embodiments, the method includes attaching the RF power die to a die support-surface of a module substrate. The RF power die is attached to the module substrate in an inverted orientation such that a frontside of the RF power die faces the module substrate. When attaching the RF power die to the module substrate, a frontside input/output interface of the RF power die is electrically coupled to corresponding substrate interconnect features of the module substrate. The method further includes providing a primary heat extraction path extending from the transistor channel of the RF power die to a topside cooling interface of the PAM in a direction opposite the module substrate.

Abstract: A device assembly includes a functional substrate having one or more electronic components formed there. The functional substrate has a cavity extending from a first surface toward a second surface of the functional substrate at a location that lacks the electronic components. The device assembly further includes a semiconductor die placed within the cavity with a pad surface of the semiconductor die being opposite to a bottom of the cavity. The functional substrate may be formed utilizing a first fabrication technology and the semiconductor die may be formed utilizing a second fabrication technology that differs from the first fabrication technology.

Abstract: Power amplifier modules (PAMs) having topside cooling interfaces are disclosed, as are methods for fabricating such PAMs. In embodiments, the method includes attaching the RF power die to a die support-surface of a module substrate. The RF power die is attached to the module substrate in an inverted orientation such that a frontside of the RF power die faces the module substrate. When attaching the RF power die to the module substrate, a frontside input/output interface of the RF power die is electrically coupled to corresponding substrate interconnect features of the module substrate. The method further includes providing a primary heat extraction path extending from the transistor channel of the RF power die to a topside cooling interface of the PAM in a direction opposite the module substrate.

Abstract: An amplifier module includes a module substrate with a mounting surface, a signal conducting layer, a ground layer, and a ground terminal pad at the mounting surface. A thermal dissipation structure extends through the module substrate. A ground contact of a power transistor die is coupled to a surface of the thermal dissipation structure. Encapsulant material covers the mounting surface of the module substrate and the power transistor die, and a surface of the encapsulant material defines a contact surface of the amplifier module. A ground terminal is embedded within the encapsulant material. The ground terminal has a proximal end coupled to the ground terminal pad, and a distal end exposed at the contact surface. The ground terminal is electrically coupled to the ground contact of the power transistor die through the ground terminal pad, the ground layer of the module substrate, and the thermal dissipation structure.

Abstract: A device assembly includes a functional substrate having one or more electronic components formed there. The functional substrate has a cavity extending from a first surface toward a second surface of the functional substrate at a location that lacks the electronic components. The device assembly further includes a semiconductor die placed within the cavity with a pad surface of the semiconductor die being opposite to a bottom of the cavity. The functional substrate may be formed utilizing a first fabrication technology and the semiconductor die may be formed utilizing a second fabrication technology that differs from the first fabrication technology.

Abstract: A device assembly includes a functional substrate having one or more electronic components formed there. The functional substrate has a cavity extending from a first surface toward a second surface of the functional substrate at a location that lacks the electronic components. The device assembly further includes a semiconductor die placed within the cavity with a pad surface of the semiconductor die being opposite to a bottom of the cavity. The functional substrate may be formed utilizing a first fabrication technology and the semiconductor die may be formed utilizing a second fabrication technology that differs from the first fabrication technology.

Abstract: An RF amplifier includes at least one harmonic trap filter with an array of shunt filter legs having a non-uniform resonance frequency distribution. The harmonic trap filter is configured to suppress frequencies in a suppression frequency range that includes harmonic frequencies of carrier frequencies in a range of carrier frequencies. Each of the shunt filter legs includes a capacitor and inductor coupled in series, and an intermediate node coupled between the capacitor and the inductor. Each intermediate node of the shunt filter leg is coupled to at least one other intermediate node of another shunt filter leg of the filter with a dampening resistor. Shunt filters at or near edges of the array are configured to have lower resonance frequencies than those at or near the center of the array to suppress excess current flow at edges of the RF amplifier.

Abstract: Embodiments of RF amplifiers and packaged RF amplifier devices each include an amplification path with a transistor die, and an output-side impedance matching circuit having a T-match circuit topology. The output-side impedance matching circuit includes a first inductive element (e.g., first wirebonds) connected between the transistor output terminal and a quasi RF cold point node, a second inductive element (e.g., second wirebonds) connected between the quasi RF cold point node and an output of the amplification path, and a first capacitance connected between the quasi RF cold point node and a ground reference node. The RF amplifiers and devices also include a baseband termination circuit connected to the quasi RF cold point node, which includes an envelope resistor, an envelope inductor, and an envelope capacitor coupled in series between the quasi RF cold point node and the ground reference node.

Abstract: A packaged RF amplifier device includes input and output leads and a transistor die. The transistor die includes a transistor with a drain-source capacitance below 0.1 picofarads per watt. The device also includes a conductive connection between the transistor output terminal and the output lead, and a baseband termination circuit between the transistor output terminal and a ground reference node. The baseband termination circuit presents a low impedance to signal energy at envelope frequencies and a high impedance to signal energy at RF frequencies. The baseband termination circuit includes an inductive element, a resistor, and a capacitor connected in series between the transistor output terminal and the ground reference node. Except for a minimal impedance transformation associated with the conductive connection, the device is unmatched between the transistor output terminal and the output lead by being devoid of impedance matching circuitry between the transistor output terminal and the output lead.

Abstract: A radio frequency amplifier includes a transistor, an input impedance matching circuit (e.g., a single-section T-match circuit or a multiple-section bandpass circuit), and a fractional harmonic resonator circuit. The input impedance matching circuit is coupled between an amplification path input and a transistor input terminal. An input of the fractional harmonic resonator circuit is coupled to the amplification path input, and an output of fractional harmonic resonator circuit is coupled to the transistor input terminal. The fractional harmonic resonator circuit is configured to resonate at a resonant frequency that is between a fundamental frequency of operation of the RF amplifier and a second harmonic of the fundamental frequency. According to a further embodiment, the fractional harmonic resonator circuit resonates at a fraction, x, of the fundamental frequency, wherein the fraction is between about 1.25 and about 1.9 (e.g., x?1.5).

Abstract: An amplifier module includes a module substrate with a mounting surface, a signal conducting layer, a ground layer, and a ground terminal pad at the mounting surface. A thermal dissipation structure extends through the module substrate. A ground contact of a power transistor die is coupled to a surface of the thermal dissipation structure. Encapsulant material covers the mounting surface of the module substrate and the power transistor die, and a surface of the encapsulant material defines a contact surface of the amplifier module. A ground terminal is embedded within the encapsulant material. The ground terminal has a proximal end coupled to the ground terminal pad, and a distal end exposed at the contact surface. The ground terminal is electrically coupled to the ground contact of the power transistor die through the ground terminal pad, the ground layer of the module substrate, and the thermal dissipation structure.

Abstract: A device assembly includes a functional substrate having one or more electronic components formed there. The functional substrate has a cavity extending from a first surface toward a second surface of the functional substrate at a location that lacks the electronic components. The device assembly further includes a semiconductor die placed within the cavity with a pad surface of the semiconductor die being opposite to a bottom of the cavity. The functional substrate may be formed utilizing a first fabrication technology and the semiconductor die may be formed utilizing a second fabrication technology that differs from the first fabrication technology.

Abstract: Radio frequency (RF) power dies having flip-chip architectures are disclosed, as are power amplifier modules (PAMs) containing such RF power dies. Embodiment of the PAM include a module substrate and an RF power die, which is mounted to a surface of the module substrate in an inverted orientation. The RF power die includes, in turn, a die body having a frontside and an opposing backside, a transistor having active regions formed in the die body, and a frontside layer system formed over the die body frontside. The frontside layer system contains patterned metal layers defining first, second, and third branched electrode structures, which are electrically coupled to the active regions of the transistor. A frontside input/output interface is formed in an outer terminal portion of the frontside layer system and contains first, second, and third bond pads electrically coupled to the first, second, and third branched electrode structures, respectively.

Abstract: A packaged RF amplifier device includes input and output leads and a transistor die. The transistor die includes a transistor with a drain-source capacitance below 0.1 picofarads per watt. The device also includes a conductive connection between the transistor output terminal and the output lead, and a baseband termination circuit between the transistor output terminal and a ground reference node. The baseband termination circuit presents a low impedance to signal energy at envelope frequencies and a high impedance to signal energy at RF frequencies. The baseband termination circuit includes an inductive element, a resistor, and a capacitor connected in series between the transistor output terminal and the ground reference node. Except for a minimal impedance transformation associated with the conductive connection, the device is unmatched between the transistor output terminal and the output lead by being devoid of impedance matching circuitry between the transistor output terminal and the output lead.

Abstract: A multiple-stage amplifier includes a driver stage die and a final stage die. The driver stage die includes a first type of semiconductor substrate (e.g., a silicon substrate), a first transistor, and an integrated portion of an interstage impedance matching circuit. A control terminal of the first transistor is electrically coupled to an RF signal input terminal of the driver stage die, and the integrated portion of the interstage impedance matching circuit is electrically coupled between a current-carrying terminal of the first transistor and an RF signal output terminal of the driver stage die. The second die includes a III-V semiconductor substrate (e.g., a GaN substrate) and a second transistor. A connection, which is a non-integrated portion of the interstage impedance matching circuit, is electrically coupled between the RF signal output terminal of the driver stage die and an RF signal input terminal of the final stage die.

Abstract: Radio frequency (RF) power dies having flip-chip architectures are disclosed, as are power amplifier modules (PAMs) containing such RF power dies. Embodiment of the PAM include a module substrate and an RF power die, which is mounted to a surface of the module substrate in an inverted orientation. The RF power die includes, in turn, a die body having a frontside and an opposing backside, a transistor having active regions formed in the die body, and a frontside layer system formed over the die body frontside. The frontside layer system contains patterned metal layers defining first, second, and third branched electrode structures, which are electrically coupled to the active regions of the transistor. A frontside input/output interface is formed in an outer terminal portion of the frontside layer system and contains first, second, and third bond pads electrically coupled to the first, second, and third branched electrode structures, respectively.

Abstract: A multiple-stage amplifier includes a driver stage die and a final stage die. The driver stage die includes a first type of semiconductor substrate (e.g., a silicon substrate), a first transistor, and an integrated portion of an interstage impedance matching circuit. A control terminal of the first transistor is electrically coupled to an RF signal input terminal of the driver stage die, and the integrated portion of the interstage impedance matching circuit is electrically coupled between a current-carrying terminal of the first transistor and an RF signal output terminal of the driver stage die. The second die includes a III-V semiconductor substrate (e.g., a GaN substrate) and a second transistor. A connection, which is a non-integrated portion of the interstage impedance matching circuit, is electrically coupled between the RF signal output terminal of the driver stage die and an RF signal input terminal of the final stage die.

Abstract: Power amplifier modules (PAMs) having topside cooling interfaces are disclosed, as are methods for fabricating such PAMs. In embodiments, the method includes attaching the RF power die to a die support-surface of a module substrate. The RF power die is attached to the module substrate in an inverted orientation such that a frontside of the RF power die faces the module substrate. When attaching the RF power die to the module substrate, a frontside input/output interface of the RF power die is electrically coupled to corresponding substrate interconnect features of the module substrate. The method further includes providing a primary heat extraction path extending from the transistor channel of the RF power die to a topside cooling interface of the PAM in a direction opposite the module substrate.

Abstract: An embodiment of a Doherty amplifier includes a module substrate, first and second surface-mount devices coupled to a top surface of the module substrate, and an impedance inverter line assembly. The first and second surface-mount devices include first and second amplifier dies, respectively. The impedance inverter line assembly is electrically connected between outputs of the first and second amplifier dies. The impedance inverter line assembly includes an impedance inverter line coupled to the module substrate, a first lead of the first surface-mount device coupled between the first amplifier die output and a proximal end of the impedance inverter line, and a second lead of the second surface-mount device coupled between the second amplifier die output and a distal end of the impedance inverter line. According to a further embodiment, the impedance inverter line assembly has a 90 degree electrical length at a fundamental operational frequency of the Doherty amplifier.

Abstract: Embodiments of a device and method are disclosed. In an embodiment, an RF amplifier includes first and second RF signal paths having RF input interfaces, RF output interfaces, and corresponding transistors connected between the respective RF input interfaces and RF output interfaces, wherein control terminals of the transistors are connected to the RF input interfaces and current conducting terminals of the transistors are connected to the corresponding RF output interfaces. The RF amplifier including a conductive path between the current conducting terminal of the first transistor and the current conducting terminal of the second transistor, wherein the conductive path includes a first inductance, a second inductance, and a capacitance electrically connected between the first inductance and the second inductance.