4-squares are not the only phased array systems of course. 

Jon Zaimes sent me the information below about his rectangular/broadside array of wire verticals for 160m at AA1K

Jon writes
"Mine isn't square but rather I have a rectangular broadside/endfire array of wire verticals on 160 meters, supported by towers and trees. Elements are 73' 6" tall with a T top hat of 58 feet. Each element has 120 radials. Currently 2 forward elements toward Europe are fed in phase through 3/4-wave 50-ohm 7/8" hardline, and two rearward elements are grounded through coils to make them resonate as reflectors. Next step is to feed the rearward pair in phase with a delay between the two sets and make it reversible, NE/SW. Spacing is 324 feet broadside and 146 feet endfire.

WW2Y and K2WI had one of these in New Jersey in the 1980s and 1990s, and K1ZM has one now at his VY2ZM QTH.

I chose this since it has more gain than a 4-square and also than my other 160-meter array, which is a 3-element and 4-element parasitic array (K3LR style, with one extra director toward NE for Europe). It's favorable f/b also makes it a fine receiving antenna, often equaling or exceeding my phased Beverages.

I also have an 80-meter broadside/endfire array under construction, which is nested inside of the 160m array and shares its radial field.

More details at www.aa1k.us."