Many taller lifters and those with a background in running-based sports (particularly track) tend to be posterior-chain dominant squatters, meaning their glutes and hams will activate much more easily than their quads when squatting.
If you have trouble feeling it in your quads during back squats, and feel it much more in your hips and lower back, try this simple tip: do front squats first. For those whose primary focus is raw poundage, this may seem like heresy. For the lifter looking for quad hypertrophy, however, this can be pure magic.
Front squats shift the focus to the quads and allow most lifters to be more comfortable squatting to depth compared to back squats. By starting your leg workout with front squats, you pre-exhaust the quads and grease the groove for the movement pattern. Yes, you'll be forced to go a little lighter on your back squats afterwards, but the long term benefits in quad strength and size make it worthwhile.
Here's How to Do It
Following your normal warm-up, do one set of 12-15 reps of front squats with just the bar. After that, the load will be based on your front squat strength. If you're not sure what your 12, 10 and 8 RMs are, give it your best guess and adjust as necessary in subsequent workouts. The goal is for the load to be challenging, but you should be nowhere near failure.
Over four sets, ramp up the weight as follows:
Set 1: 8 reps with a weight you could front squat 12-15 times without much trouble.
Set 2: 8 reps with your 12 RM
Set 3: 5 reps with your 10 RM
Set 4: 5 reps with your 8 RM
Now you're ready to go do your back squat workout as planned.