CWNP CWNA-109 Dumps Questions Answers

Return loss is a measure of how well the components of an RF system are matched in terms of their impedance. Impedance is the opposition to the flow of alternating current in a circuit, and it depends on the frequency, resistance, capacitance, and inductance of the components. When the impedance of the source, the transmission line, and the load are not equal, some of the power is reflected back to the source, causing a loss of forward power. This loss is expressed in decibels (dB) as return loss. The higher the return loss, the lower the reflection and the better the impedance matching. Conversely, the lower the return loss, the higher the reflection and the worse the impedance matching.

VSWR (Voltage Standing Wave Ratio) is another way of expressing the same concept. It is the ratio of the maximum voltage to the minimum voltage along a transmission line due to the interference of the incident and reflected waves. A VSWR of 1:1 means that there is no reflection and perfect impedance matching. A VSWR higher than 1:1 means that there is some reflection and impedance mismatch. The higher the VSWR, the higher the reflection and the lower the return loss.

Therefore, a significant impedance mismatch between components in an RF system will cause high reflection, high VSWR, and low return loss.

A BSS (Basic Service Set) is a WLAN use case that represents an 802.11-based network that uses an AP (Access Point) and has several connecting clients. The AP acts as a central point of coordination and communication for the clients, which can include iPhones, iPads, laptops, desktops, or any other devices that have Wi-Fi capabilities. A BSS can be identified by a unique BSSID (Basic Service Set Identifier), which is usually the MAC address of the AP’s radio interface. A BSS can also be associated with an SSID (Service Set Identifier), which is a human-readable name that identifies the network. References: , Chapter 1, page 23; , Section 1.1

According to the CWNA Official Study Guide (CWNA-109), Chapter 4: Antennas and Accessories, antenna gain is a measure of how effectively an antenna focuses energy in a particular direction. When a passive antenna with a higher gain is used, it does not increase the transmitted power — instead, it focuses the RF energy more narrowly, creating a stronger signal in a smaller area.

“As the gain of an antenna increases, the beamwidth of the antenna decreases. This is because a higher gain antenna focuses energy more narrowly in one direction. While this increases range in that direction, it reduces coverage in other directions.”

— CWNA-108 Study Guide, Chapter 4, Antenna Concepts and Beamwidth, p. 165–166

Thus, when you replace an antenna with one of higher passive gain, the beamwidth decreases while range in the direction of focus increases.