In link budgeting, how does increasing antenna gain affect transmit power for a given range?

• A. It increases link margin, requiring more transmit power for the same range
• B. It reduces the need for any transmit power
• C. It has no effect on range or power
• D. It increases range for the same power

Answer: (D)

Higher antenna gain concentrates more energy toward the receiver, boosting the effective power seen at the other end (the EIRP goes up). In a link-budget view, the received power scales with the product of transmit gain and receive gain; increasing transmit gain while keeping power and other losses fixed raises the received signal level. That means the same transmit power can reach farther before the signal falls below the minimum receiver threshold, so range increases. The practical trade-off is that higher gain means a narrower beam, requiring precise alignment, but the key effect on the link is extended range for the same power.