Transistors - FETs, MOSFETs

Transistors - FETs, MOSFETs - RF

Part Number	Description / PDF	Quantity
STAC4933 STMicroelectronics	MOSF RF N CH 200V 40A STAC177B	0
PD55015-E STMicroelectronics	FET RF 40V 500MHZ PWRSO-10	328
PD85006L-E STMicroelectronics	TRANS RF POWER POWERFLAT5X5	0
PD85004 STMicroelectronics	FET RF 40V 870MHZ	0
PD84002 STMicroelectronics	FET RF 25V 870MHZ	2073
SD2941-10W STMicroelectronics	IC TRANS RF HF/VHF/UHF M174	0
PD57018-E STMicroelectronics	FET RF 65V 945MHZ PWRSO10	24
PD55008-E STMicroelectronics	FET RF 40V 500MHZ PWRSO10	90
PD55003-E STMicroelectronics	FET RF 40V 500MHZ PWRSO10 PD55003-E	3600
SD56120C STMicroelectronics	FET RF 72V 860MHZ M246	0
SD2942W STMicroelectronics	IC TRANS RF HF/VHF/UHF M244	0
STAC2942BW STMicroelectronics	TRANS RF PWR N-CH 350W STAC244B	25
SD2931-12MR STMicroelectronics	IC TRANS RF/VHF DMOS M174MR	0
SD2943W STMicroelectronics	TRANS RF N-CH HF/VHF/UHF M177	26
PD85035S-E STMicroelectronics	FET RF 40V 870MHZ	0
PD54008TR-E STMicroelectronics	TRANS RF PWR N-CH POWERSO-10RF	0
PD85025TR-E STMicroelectronics	TRANS RF N-CH FET POWERSO-10RF	0
PD20015C STMicroelectronics	FET RF 40V 2GHZ M243	0
SD3931-10 STMicroelectronics	IC RF PWR TRANS HF/VHF/UHF M174	0
PD20010TR-E STMicroelectronics	TRANS N-CH 40V POWERSO-10RF FORM	0

Transistors - FETs, MOSFETs - RF

1. Overview

RF FETs and MOSFETs are critical semiconductor devices designed for high-frequency signal amplification and switching in radio frequency (RF) applications. These transistors operate efficiently in microwave and RF circuits, enabling wireless communication, radar systems, and broadcasting equipment. Their ability to handle high frequencies (typically above 1 MHz) with minimal noise and distortion makes them indispensable in modern telecommunications infrastructure.

2. Main Types and Functional Classification

Type	Functional Features	Application Examples
Junction FET (JFET)	Voltage-controlled device with low noise and high input impedance	Low-noise amplifiers in RF receivers
MESFET	Metal-Semiconductor FET with GaAs substrate for high-speed operation	Satellite communication systems
HEMT/PHEMT	High-electron-mobility transistor with pseudomorphic structures	5G base stations, microwave amplifiers
LDMOS	Lateral Diffused MOSFET with high power density and thermal stability	Cellular base station amplifiers
GaN HEMT	Gallium Nitride-based HEMT for ultra-high frequency/power	Radar systems, 5G mmWave

3. Structure and Composition

RF FETs typically feature a three-terminal structure (source, gate, drain) with a semiconductor channel (Si, GaAs, or GaN). The gate region uses Schottky contacts (MESFET) or insulated layers (MOSFET). Advanced devices like HEMTs employ heterojunctions between different semiconductor materials (e.g., AlGaN/GaN) to enhance electron mobility. Packaging includes ceramic or plastic enclosures with RF-compatible connectors to minimize parasitic capacitance and inductance.

4. Key Technical Specifications

Parameter	Description	Importance
Frequency Range	Operational bandwidth (e.g., 0.1-6 GHz)	Determines application suitability
Power Output (P1dB)	1dB compression point (e.g., 10-500W)	Measures linearity and saturation
Gain (S21)	Signal amplification ratio (e.g., 10-30 dB)	System sensitivity indicator
Efficiency (PAE)	Power-added efficiency (e.g., 40-75%)	Energy consumption metric
Input/Output VSWR	Voltage Standing Wave Ratio (e.g., <2:1)	Mismatch loss assessment

5. Application Fields

Telecommunications: 5G/4G base stations, small cells, fiber-optic networks
Defense: Radar systems, electronic warfare, UAV communication
Broadcasting: FM/TV transmitters, satellite uplinks
Medical: MRI machines, RF ablation equipment
Industrial: Plasma generators, RFID readers

6. Leading Manufacturers and Products

Manufacturer	Representative Product	Key Specifications
NXP Semiconductors	MRF1K50GN	50W GaN HEMT, 1.8-2.7GHz, 70% PAE
Wolfspeed (Cree)	CGH4G090400F	400W GaN HEMT, 900MHz, 10:1 VSWR ruggedness
Infineon	BLS14H10LS-250	250W LDMOS, 1.8-2.2GHz, 14dB gain
MACOM	NPT1007	SiGe HBT, 7GHz, 18dB gain for 5G

7. Selection Recommendations

Match operating frequency to device transition frequency (f_T)
Verify power handling with derating curves under working temperatures
Assess package thermal resistance (R_th) for longevity
Compare S-parameters for impedance matching requirements
Consider ESD protection and ruggedness for field conditions

8. Industry Trends

Key trends include: - Wide bandgap materials (GaN/SiC) enabling higher efficiency (>80%) at mmWave frequencies - 3D packaging for reduced parasitics in 5G massive MIMO systems - Integrated RF frontend modules (FEM) with on-chip matching networks - AI-driven design optimization for complex impedance matching - Growing adoption of GaN-on-diamond substrates for thermal management