Overview of UHF connectors:
UHF connectors are a type of RF connector with a long history, originating in the 1930s when "UHF" referred to a frequency range above 30 MHz. Although the definition of the UHF band has since changed to 300 MHz to 3 GHz, the connector has retained the name due to historical reasons. Its characteristics are more suited for frequencies around 100 MHz or lower, which is typically considered the VHF band today. A notable feature of UHF connectors is the relatively thick central conductor inside the plug, with a diameter of approximately 4 mm. The connection and securing method uses internal threads on the plug and external threads on the socket, which provides a stable connection.
Why is the size of UHF connectors larger than typical connectors?
- Frequency Characteristics Requirement
UHF connectors are primarily used in the ultra-high-frequency range (though they are often used in the VHF range today). To effectively transmit signals and avoid excessive signal attenuation and reflection, the connector size needs to be appropriately matched to the wavelength. The longer wavelength allows for the use of larger connector structures to guide and transmit the signal efficiently. For example, the UHF connector has a thicker central conductor (about 4 mm in diameter), which helps to transmit signals effectively at lower frequencies.
- Power Handling Requirements
UHF connectors are typically used in RF applications that require higher power. To handle this higher power, they need to provide enough space for heat dissipation and to carry larger currents. Larger connector structures allow for thicker conductor materials, which can carry higher currents without overheating. Additionally, the larger size helps with heat dissipation—there is enough space between the central conductor and the shield to better dissipate heat generated during the transmission of high-power signals. This allows UHF connectors to handle RF peak power levels over 1 kW, with some models even supporting peak voltages over 4 kV.
- Mechanical Strength and Stability Considerations
UHF connectors are often used in complex environments, such as industrial and communication settings, where good mechanical strength and connection stability are required. The larger size allows the connector components to be thicker and more robust. For example, the internal threads on the plug and external threads on the socket interlock to provide a more secure connection, able to withstand impacts, vibrations, and other external forces without loosening or damaging. This ensures the reliability of RF signal transmission.
Advantages and Disadvantages of UHF Connectors:
Advantages:
- Relatively large size, making them easier to handle and connect.
- Capable of handling higher power, suitable for RF applications requiring higher power.
- Long service life and good reliability.
Disadvantages:
- The non-constant surge impedance limits its application at higher frequencies.
- Lack of waterproofing requires special attention to protection when used outdoors or in humid environments.
- Compared to modern miniaturized, high-performance connectors, UHF connectors are larger and heavier.