The WNHD3004's design is quite different than your standard 802.11n AP / bridge. First, it's based on Quantenna devices and second, it has four receive / transmit channels.
Since the FCC photos were fuzzy, I opened one up to ID the components. Figure 2 shows the top inside view, which differs from the FCC photo in that the main Quantenna SoC in the silver package doesn't have a heatsink.
Figure 2: WNHD3004 inside top view
I expected to find the QHS600 as the main SoC, but instead found a Quantenna QT1018BH, which there is no mention of on Quantenna's website. An Atheros AR8236 handles the four switched 10/100 Ethernet ports and there is 64 MB of RAM and 8 MB of flash to support the QT1018BH.
Figure 3: WNHD3004 inside bottom view
You can see these components more clearly, except for the Intel flash device on the bottom of the board, in Figure 4.
Figure 4: WNHD3004 top component detail
I didn't want to risk disturbing the RF integrity by prying off the RF shield, so I turned to the FCC ID photos for a peek inside the can. Figure 5 shows a pretty clear close-up of the RF area. The two larger devices at the bottom of the photo are Quantenna QT1518Bs. But the four smaller devices at the top are way too small to make out their part numbers.
Figure 5: WNHD3004 RF section detail
As is NETGEAR's practice, the WNHD3004 has etched-on-board antennas. Figure 6 shows a close-up of the top antenna area, where four antennae are clearly visible.
Figure 6: WNHD3004 top antenna detail
Figure 7 shows the bottom of the board, with what looks like ground plane running under the top antenna area. You can also see the heatsink plate that is coupled to the four tiny devices (most likely power amplifiers) on the top side of the board via thermal pads.