A TNC connector is a type of coaxial connector that is very similar in design and function to the BNC connector. It is often used in RF (Radio Frequency) and microwave applications where a secure connection and high-frequency performance are required. While the BNC connector is typically used up to around 4 GHz, the TNC connector extends the frequency range up to approximately 11 GHz. This makes it suitable for higher frequency applications that require improved performance.