Low Phase Noise Amplifiers

New Pasternack´s family of low phase noise amplifiers are commonly used to help optimize the sensitivity and dynamic range of higher performing test, radar, and communication receiver designs where performance is dependent on how effectively the smallest and largest signal levels can be processed.

Additionally, for systems that require amplification of weaker signals close to the noise floor, the low phase noise performance of these amplifiers can help reduce unwanted noise and distortion that can inhibit the quality of the transmitted signal. Typical applications for these low phase noise amplifiers include electronic warfare, microwave radio, VSAT, radar, space systems, test Instrumentation and telecom infrastructure.

Features include:
• Broadband Frequencies from 1.5 GHz to 18 GHz
• Typical Phase Noise @ 10 KHz Offset as low as -180 dBc/Hz
• Gain Levels from 9 dB to 14 dB
• Highly Linear GaAs MMIC Technology
• Output IP3 Linearity up to +34 dBm
• Psat levels up to +25 dBm
• Input/Output ports are internally matched to 50 Ohms and are DC Blocked
• Hermetically Sealed Packages support Field Replaceable SMA Connectors
• Models are MIL-Spec Compliant

Pasternack´s new Low Phase Noise Amplifiers are in-stock and available to ship today.
For detailed information on these products, please contact Vermont Rep.

Reverse Polarity Connectors Defined

A reverse polarity coax connector is a variation of a standard polarized connector in which the gender of the interface has been reversed. The term “reverse polarity” refers not to the signal polarity of the connector itself, but to the gender of the center contact pin.

A reverse polarized connector will have the same external housing (body) as a standard connector (jack or plug threading), but the center pin is altered to be reversed. Thus, a reverse polarized jack has a male pin in place of the standard female type pin/receptacle and a reverse polarized plug will have a center receptacle (female) instead of a male pin.

The chart below outlines reverse polarized connector body and pin options:

Reverse polarity coaxial connectors were developed to separate professional grade and commercially available components and equipment to comply with FCC regulations. The idea was that reverse polarized connectors would not be readily available or accessible to the general consumer audience so they would not try to or be able to connect certain gain components or equipment. (Example: switching a radio to a higher gain antenna) Since then, the rules have changed and today several variations of reverse polarity connectors are readily available, allowing more design options to more people.

The most common reverse polarized connector types are RP-SMA, RP-BNC, RP Type-N and RP-TNC. They are typically used for Wi-Fi, Cellular, RF and GPS antenna and equipment applications.

The connector body is commonly referred to as a “plug” or “jack” (for example reverse polarity TNC plug) instead of “male” or “female”. The terms male and female are used when describing the center pin of a reverse polarized coax connector.

For a complete listing of our reverse polarity products, please use the links below.

Bi-Directional Amplifiers Explained

A Bi-Directional amplifier (BDA) is a device that locates a wireless signal, amplifies it, and then rebroadcasts it throughout a building or area.

The backbone of most range or signal extending technologies is a relatively simple dual amplifier device with an integrated low noise amplifier (LNA) and power amplifier (PA). The Bi-Directional amplifier either enables a weak incoming signal to be amplified and retransmitted to extend its signal, in both directions, or can be used to either transmit a signal from a radio and pre-amplify received signals using the same antenna.

Importantly, there are two main types of Bi-Directional amplifiers, full-duplex and half-duplex. The term, duplex, implies that a device is capable of both transmission and reception simultaneously. Hence, half-duplex implies that the device can perform both trafuncnsmission and reception, just not simultaneously.

Typically with Bi-Directional amplifiers, the transmission and reception tion are selected with switch networks at the ports, or by the use of intelligent biasing. Different methods of switching or biasing could cause transient impedance scenarios, loading of the transmitter PA, or overloading of the receiver LNA if not properly configured or timed. These directions should be detailed in thedevice’s data sheet as switching time, or with a manufacturer provided control sequence diagram.

A simple switched Bi-Directional amplifier topology with a bandpass filter in the receive signal chain can be used as a half-duplex repeater with the transmit/receive control circuitry.

On the other hand, full-duplex Bi-Directional amplifiers can perform both reception and transmission, simultaneously. This is often enabled by having a separate transmit and receive frequency – as seen in many cellular and satellite communication technologies, or frequency division multiplexing (FDM). With this topology, duplex filters are used to attenuate the transmit signal in the receive signal chain.

To view our inventory of Bi-Directional Amplifiers, please use the links below.

What is PIM? Passive Intermodulation Explained

What is PIM?

PIM, or Passive Intermodulation, is a type of signal distortion that has become increasingly important to detect and mitigate since LTE networks are particularly sensitive to it.

PIM is created when there are two or more carrier frequencies exposed to non-linear mixing. The resulting signal will contain additional, unwanted frequencies or intermodulation products. As the “Passive” portion of the name implies, this non-linear mixing does not involve active devices and is frequently caused by the metallic materials and workmanship of the interconnects and other passive components in the system. Examples of causes of non-linear mixing:

– Imperfect electrical connections: surfaces are never perfectly smooth so the areas of contact can have high current densities which can cause heating through a restricted conduction path causing a resistance change. For this reason connectors should always be tightened to the correct torque.

– Most metal surfaces have at least a thin layer of oxide which can cause tunneling, or simply cause a reduced area of conduction. Some believe that this produces the Shottky effect. This is why a rusty bolt or metal roof near a cell tower can produce a strong PIM distortion signal.

– Ferromagnetic material: materials such as iron can generate large PIM distortion and should not be used in cellular systems.

As wireless networks become more complex with multiple technologies and system generations in use at a single site, the signals combine to generate this undesired distortion, which interferes with the LTE signals. Antennas, diplexers, cables, and dirty or loose connectors can be sources of PIM, as well as damaged RF equipment or metal objects near or at a distance from the cell site.

PIM interference can have substantial impacts on the performance of LTE networks, which is why it is so important to wireless operators and their contractors to be able to test for, locate and mitigate PIM. Acceptable PIM levels vary by system but as an example Test Company Anritsu said that drive tests have found an 18% drop in download speeds when PIM levels were increased from -125 dBm to -105 dBm, even though the latter number can be considered an acceptable PIM level.

Where is PIM tested?

Individual components are often tested for PIM both in the design and production processes in order to ensure that they are not significant PIM sources once they are installed – however, installation is still a critical piece of PIM mitigation because proper connections are critical. In the case of distributed antenna systems, in some instances the system is tested for PIM as well as individual components. PIM-certified equipment is becoming more common. Antennas, for example, may be PIM-certified to a level of -150 dBc and those requirements are increasingly strict.

PIM is also assessed during the siting process for cellular sites, ideally before the cell site and antennas are placed as well as during the installation process.

Pasternak provides Low PIM cable assemblies, connectors, adapters, antennas and tappers designed to address applications where PIM can be an issue.

Flexible Waveguides Solve Difficult Application Challenges

In many installations and test bench scenarios, a precisely designed rigid waveguide structure with the proper flange and orientation is not readily available. Lead times of several weeks to months are common to receive the correct part. This is not always convenient in a design, repair, or replacement situation.

Flexible waveguides at various lengths enable twisting and flexing over a considerable range, which can solve many installation problems caused by misalignment. Another example is in microwave antenna or parabolic reflector positioning applications, which may require physical adjustment many times to ensure proper alignment. In these applications, flexible waveguides enable a much wider range of alignment possibilities, without sacrificing the cost or time of waiting for customized parts.

There are applications where even rigid waveguide structures may not provide the necessary features for solving several installation problems. In applications that produce a wide range of vibration, shock, or creep, a flexible waveguide may be preferred over a rigid waveguide, as the flexible waveguide can provide vibration, shock, and creep isolation to more sensitive waveguide parts. Additionally, in applications with high temperature variability, thermal expansion and contraction can lead to damage of even mechanically robust interconnects and structures. Flexguide is able to contract and expand slightly to accommodate thermal variations and in situations with extreme thermal expansion/contraction issues, an additional bend loop can be incorporated to enable greater displacement.

For additional information on these flexible waveguide products and solutions, please contact Vermont Rep.

USB-Controlled PLL Frequency Synthesizers

Pasternack is pleased to offer you 6 new models of PLL Frequency Synthesizers that cover broad frequencies ranging from 25 MHz to 27 GHz. These RF synthesizers allow designers to generate a variety of output frequencies as multiples of a single reference frequency for test and measurement purposes. These modules also offer high levels of stability and accuracy with exceptional phase noise characteristics that allows components in the signal chain to perform at optimum levels with very little distortion.

Features include:
• SMA connectorized packages
• Phase Locked Loop (PLL) Synthesizers
• USB GUI interface with a PC computer
• Broadband Frequency coverage from 25 MHz to 27 GHz
• Broad tuning range for output attenuation and output power
• Frequency Resolution step size down to 1 MHz
• Functional LED indicators
• Downloadable user manual and command control VISA software package

Our new USB-controlled PLL Frequency Synthesizers are in-stock and available to ship today. For detailed information on these products, please contact Vermont Rep.