B737-700 INBOUND TO SFO RWY 28L EXPERIENCED EQUIP PROBLEM; EXECUTED GAR; REPORTER COMMENTING THAT NCT KEEPS SFO ARR'S TOO HIGH TOO LONG.

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PASSING SFO VOR; HDG 140 DEGS FOR VECTOR TO RWY 28L. WE BOTH COMMENTED AND DISCUSSED THE CONSISTENT POOR/TIGHT VECTORS AND LATE DSCNT CLRNCS AT SFO GIVEN BY NORCAL. WE CONFIGURED EARLY; AND RECEIVING THE TYPICAL EARLY/SHORT BASE TURN (RELATIVE TO ALT) WE PUT THE GEAR DOWN VERY EARLY. BOTH NAV RADIOS WERE TUNED AND IDENTED TO RWY 28L. RECEIVING VECTOR TO FINAL; I NOTICED THAT MY LOC AND GLIDEPATH WERE NOT STEADY; BUT RATHER WERE BLINKING ON AND OFF. I ALSO GOT MULTIPLE A111 ARMING PROMPTS ON THE HGS (NORMALLY ONLY 2 PROMPTS ARE GIVEN AND CANCELED IF NOT NEEDED). THIS ALL OCCURRED VERY CLOSE TO COURSE INTERCEPT. AS WE APCHED THE LOC COURSE (AS NOTED ON THE NAV DISPLAY) I NOTICED THE AUTOPLT DID NOT CAPTURE THE COURSE; NOR WAS MY LOC SHOWING IT WAS ACTIVE. I PROMPTLY TURNED OFF THE AUTOPLT AND AUTOTHROTTLES AND BEGAN A HARD TURN BACK TO REINTERCEPT AFTER HAVING FLOWN THROUGH THE RWY 28L LOC. I KNEW THAT THERE WAS TFC ON RWY 28R AND ATC DID SAY THEY HAD US IN SIGHT. WE BOTH LOOKED AT THE FREQS AND NOTED THEY WERE SET CORRECTLY. I THEN NOTED THAT MY APCH REF (ILS FREQ AND COURSE IN THE UPPER L OF THE PFD) WAS RAPIDLY CHANGING BACK AND FORTH FROM THE ILS FREQ TO THE ILS IDENTIFIER. THE FO'S SIDE WAS STEADY. BY THIS TIME; THE RWY WAS IN SIGHT AND WE WERE LINED UP BUT TOO HIGH; SO WE ELECTED TO GO AROUND. WE NOTIFIED SFO TWR AND NORCAL OF THE PROB (IN THE EVENT IT WAS AN ARPT PROB AND NOT OUR ACFT). NEITHER SFO TWR; NOR NORCAL MADE ANY MENTION OF OUR INCURSION INTO RWY 28R AIRSPACE. DURING THE SECOND APCH; THIS TIME TO RWY 28R; I NOTED THE SAME ANOMALY ON MY PFD. WE QUICKLY SWITCHED PF ROLES. WHEN WE ADVISED NORCAL; THEY WARNED A FLT; WHO ALSO RPTED PROBS. WE LANDED WITHOUT INCIDENT. UPON ARR AT THE GATE WE NOTIFIED MAINT AND WROTE UP THE DISCREPANCY. THE MAINT TECH LATER SAID HE NOTED A FAULT ON THE #1 RECEIVER. WHEN HE SWAPPED #1 FOR #2; THE FAULT DISAPPEARED. THE FAULT REMAINED CLR WHEN HE PUT #1 BACK IN ITS ORIGINAL PLACE. THE ACFT WAS DOWNGRADED TO CAT1; AND WE DEPARTED FOR ZZZ. THE FLT WAS COMPLETED WITH NO ADDITIONAL PROBS. NORCAL NEEDS TO STOP VECTORING ACFT TO FINAL WHEN THEY ARE TOO HIGH. SFO RPTED 9 MI VISIBILITY; BUT IT WAS NOT MORE THAN 5 MI DUE TO SMOKE.