As mentioned, the Suchoi-11 was a close derivative of the Su-9 which in turn was a delta winged version interceptor of the Su-7. However, it never lived up to the expectation and thus Suchoi developed the Su-11 into the Su-15 Flagon. The common feature to all three planes was the use of the Delta wings with conventional tail controls.
Here are pictures of the Suchoi 7, 9
and also with the Su-15 I have built over the years.
Isaac