SBL-1 double balanced mixer

Can someone exxplain me how this attached circuit change polarisation for input RF 18Mhz wave? I rearly don't get it. As pulse this circuit gets square 25us 5V pusle, next some delay 0V and second pulse 50us 5V. At output to preamp it give 90 degree first pulse and 180 degree second. How SBL-1 convert polarisation? Is there any another way to get the same effect? Maybe IC4060? I'm looking for something that I can simulate on any free circuit simulator. This SBL-1 I cant find as componet to use on any free circuit simulator. Is on this circuit phase mean the same as polarisation?