Antennas, Coaxial, Connectors and Mounting brackets

Elsema offers a wide selection of antennas, designed by our skilled RF engineers using the latest technology and advanced test equipment from Rohde & Schwarz. Our standard antennas, available for 4G, LTE, 915MHz, 433MHz, and 151MHz, are always in stock. Additionally, we can customize antennas with different frequency bands, connectors, or coaxial cables to meet specific customer needs.

When choosing the right antenna, it’s crucial to match the antenna frequency to the equipment being used. Most of Elsema’s radio equipment operates on 4G, 915MHz, 433MHz, and 151MHz frequencies. For higher frequencies, such as 4G, 433MHz and 915MHz, it’s important to use low-loss coaxial cables and high-quality connectors. These factors are essential for ensuring optimal signal transmission and reliable performance in all applications.

As a rule, we use high-quality SMA connectors for frequencies above 300MHz. For frequencies below 300MHz, we prefer PL259 and SO239 connectors. However, we avoid using PL259 and SO239 connectors above 300MHz since they don’t perform well at higher frequencies. On special request, we also offer connectors like N, BNC, MCX, and MMCX.

When choosing the correct antenna, consider gain, SWR, and the coaxial cable type. Antenna gain measures in decibels (dBi) relative to an isotropic radiator, which radiates equally in all directions. You can also measure gain in dBd, where 1 dBd equals dBi minus 2.15.These factors ensure the antenna performs efficiently in your specific setup.

The SWR measures the mismatch between the antenna (load) and the transmission line’s impedance. Ideally, an SWR of 1 represents a perfect match, meaning no signal reflections occur along the transmission line. However, an SWR below 1.5:1 is generally considered good, while anything above 2:1 is usually unacceptable. This often indicates an issue with the antenna. For more details, refer to the table for converting SWR into power transmitted or reflected.

In addition, all coaxial cables experience attenuation. Therefore, using high-quality coaxial cables helps minimize this loss and maintain better signal transmission. To compare various types of coaxial cables, refer to the coaxial cable data table, which outlines the most common options and their characteristics.