The pilot reported that after about 15 minutes of flying around the airport, he returned for landing. While he was on the base leg of the airport traffic pattern, he thought the airplane was a little high, so he reduced engine power so he could join the final approach on a 3-degree glide slope. As he entered the final approach, he added a little power and aimed for a touchdown point about 1,000 ft down the runway, which was sloped; it was higher on the approach end and dipped down in the middle. During short final, he realized that he descended below the glide path and his sink rate was higher than expected, so he added engine power, but shortly after doing so, he felt a "bang" and jolt, followed by a pitch down and impact with the terrain. The airplane struck a localizer antenna near the approach end of the runway and skidded to a stop in the grass. The forward portion of the fuselage, right wing, and horizontal stabilizer were substantially damaged. The pilot reported that there were no preaccident mechanical malfunctions or failures of the airplane that would have precluded normal operation.