The only way it'll affect each other is IF you 1) Use the same channel, and 2) Have the same wireless SSID.
If your other connection is let's say on a default channel of 11, then you would want to set your D-Link DGL-4300 on channel 11 manually, and set it to something else. Use a different method of encryption also, and a different passphrase. This will definitely assure that it won't overlap or cause any problems.