Navigating Amplifier Thermal Analysis

Navigating Amplifier Thermal Analysis

Mini-Circuits has a longstanding legacy of fully specifying the thermal performance of our amplifiers, with or without a Mini-Circuits-supplied heatsink. Recently, it has become so commonplace for custom heatsinks to be utilized with Mini-Circuits power amplifiers that the power amplifier thermal characteristics are now expressed differently. Although the thermal resistance of the Mini-Circuits-supplied heatsink is no longer explicitly provided for newer models this is easily calculated from the specifications given for any model power amplifier. Basic calculations are all that is needed to arrive at any parameter of interest when analyzing thermal characteristics of any Mini-Circuits power amplifier.

RF/Microwave Equalizers: An Essential Ingredient for the Modern System Designer

Figure 3: Two-stage 400-6000 MHz LNA block diagram.

The need for equalization has become commonplace throughout the RF/microwave/millimeter wave frequency ranges. Modern military, satellite and wireless communications systems transmit and receive signals with relatively high instantaneous bandwidths. Gain variation across the signal bandwidth induces distortion in the transmitted or received signal because not all frequency components are amplified equally1. In other words, for multi-phase, multi-amplitude-level-modulated systems, unintended amplitude differences (i.e. due to gain changes) over the occupied bandwidth introduce errors, leading to incorrect interpretation of the signal and an increase in system bit error rate (BER)2

Wideband Connectorized Amplifiers Support Over-The-Air (OTA) Transmitter & Receiver Testing for 5G FR2 Bands

Figure 1: Simplified diagram of a Total Radiated Power (TRP) test setup.

The advent of 5G networks has already begun ushering in a whole new generation of wireless devices and applications, and device manufacturers are racing to be the first to market. In order to meet the 5G standard for commercial wireless communication, device manufacturers need to develop powerful transmitters and receivers that operate in the millimeter wave range. This comes with a number of challenges, one of which is testing and qualification. Due to the wireless nature of these devices, manufacturers need to conduct testing in real-world conditions, which isn’t possible using the conventional approach of connecting devices under test (DUTs) to instruments with coaxial cables. Over-the-air (OTA) testing allows engineers to more realistically simulate real-world device performance in the lab environment.

A Quick Guide to RF & Microwave Filter Topologies

Figure 1: Ideal filter transfer function.

RF / microwave filters are essential building blocks of practically every wireless transceiver design. Filters block undesired signals outside the application operating bandwidth while passing in-band signals through to the rest of the signal chain. At a high level, filters can be described by their response, that is, the general shape of the S21 curve in the passband, transition, and stopband. A theoretically ideal filter would have a “brick wall” response, exhibiting 0 dB insertion loss in the passband, infinite rejection beyond the frequency cut-off fc and a transition from the passband to the stopband in 0 Hz

Choosing an LNA for your Receiver Front End

Choosing an LNA for your Receiver Front End

A low-noise amplifier (LNA), which Mini-Circuits defines as any amplifier with a noise figure (NF) below 3 dB, should usually be used at the front end of an RF or microwave receiver chain for ideal performance. This single component has outsized effects on the rest of the signal chain, and that’s why choosing an LNA is such a critical decision. Mini-Circuits stands ready to help our customers through this process, so let’s take a look at what goes into it.

Wideband Connectorized Amplifiers for mmWave Over-The-Air (OTA) Transmitter & Receiver Testing

Figure 1: Simplified diagram of a total radiated power (TRP) test setup.

The advent of 5G networks has already begun ushering in a whole new generation of wireless devices and applications, and device manufacturers are racing to be the first market. In order to meet the 5G standard for commercial wireless communication, device manufacturers need to develop powerful transmitters and receivers that operate in the millimeter wave range, which comes with a number of challenges, one of which is testing and qualification. Due to the wireless nature of these devices, manufactures need to conduct testing in real-world conditions, which isn’t possible using the conventional approach of connecting devices under test (DUTs) to instruments with coaxial cables. Over-the-air (OTA) allows engineers to more realistically simulate real-world device performance in the lab environment.

Distributed RF Amplifier Designs for Ultra-Wideband Applications

Figure 2: Noise figure and gain circles on the source reflection plane.

Amplifiers are used in RF systems to boost the power level of a signal. Conventional RF amplifiers are designed using reactive elements to achieve matching to the characteristic impedance of a circuit within the specified operating frequency range for a given system. Reactively matched amplifiers allow designers to optimize performance parameters for a broad range of system requirements. Combined with techniques like balancing, using 90˚ hybrids and negative feedback, they can support bandwidths as wide as about 10:1.

Novel MMIC Splitter/Combiner Designs Achieve High Isolation Down to DC

Figure 1: Resistive power splitter / combiner circuit schematic

Traditionally, DC power splitter / combiner circuits are implemented with resistors. A simple resistive power splitter / combiner circuit schematic is shown in Figure 1. If Z0 = 50W, and ports 2 and 3 are terminated in 50W, then port 1 is matched to 50W as well, so Z0 / 3 = 16.7W. Resistive power splitter / combiner circuits typically have poor isolation between ports at DC and over frequency.

MMIC Amplifiers with Shutdown and Bypass Features De-Mystified

Figure 1: Simplified schematic of an RF amplifier with shutdown functionality

Mini-Circuits’ TSS- and TSY-families of MMIC amplifiers feature a versatile combination of performance characteristics including high dynamic range and very low noise figure with wideband frequency coverage from VHF up to mmWave applications. These product families also include additional features of shutdown and bypass functionality. These features often lead to customer questions about the difference between bypass and shutdown, which products have which features, and the benefits of each. This article will explain how these features work, and provide an overview of some of the applications are where shutdown and bypass functions are most commonly used.

MMIC Technologies: Pseudomorphic High Electron Mobility Transistor (pHEMT)

Figure 2: GaAs primitive cell

Pseudomorphic High-Electron-Mobility-Transistor (pHEMT) is one technology Monolithic Microwave Integrated Circuit (MMIC) designers and fabs use to develop and manufacture microwave integrated circuits. pHEMT has gained popularity as a building block of many MMICs produced by electronics manufacturers like Mini-Circuits due to its superior wideband performance characteristics including low noise figure, high OIP3 and excellent reliability up to 40 GHz and beyond. pHEMT uses heterojunctions between semiconductors of different compositions and bandgaps to achieve outstanding high-frequency performance. This article delves into the physics of pHEMT operation, advantage, and reliability test results. A link to a summary of Mini-Circuits’ pHEMT products is also provided.