PWM signal problem

batfink, he result is identical in either AC or DC couplings.

  -- every 3.84 uS - short pulse generates clock Tick 
  process (Clk)
  begin
  if (rising_edge(Clk)) then
       ClkCount <= ClkCount+1;
       if (ClkCount = 96) then     
     ClkTick <='1';
     ClkCount <= (others =>'0');
    else
     ClkTick <='0';
       end if;
   end if;
  end process;
 
  -- resets PulseCounter at 30 ms 
  -- PulseCounter is 13 bits long shared variable
  process (Clk,ClkTick)
  begin
   if (rising_edge(Clk)) then
    if(ClkTick ='1') then 
       PulseCounter := PulseCounter+1;
       if (PulseCounter = PulsePeriodRes) then
    PulseCounter := (others =>'0');
  end if;
  end if;
  end if;
  end process;
 
 -- Rxd_data is the compare value 
  process (Clk)
  begin
   if (rising_edge(Clk)) then
    if(PulseCounter<  Rxd_data) then
     Pwm_out<='1';
    else
     Pwm_out<='0';
    end if; 
   end if;
  end process;