PHPExcel download using ajax call

PHP

$objWriter = new PHPExcel_Writer_Excel5($objPHPExcel);
ob_start();
$objWriter->save("php://output");
$xlsData = ob_get_contents();
ob_end_clean();

$response =  array(
        'op' => 'ok',
        'file' => "data:application/vnd.ms-excel;base64,".base64_encode($xlsData)
    );

die(json_encode($response));

JS

$.ajax({
    type:'POST',
    url:"MY_URL.php",
    data: {},
    dataType:'json'
}).done(function(data){
    var $a = $("<a>");
    $a.attr("href",data.file);
    $("body").append($a);
    $a.attr("download","file.xls");
    $a[0].click();
    $a.remove();
});

add target=_blank in your ajax success function like below

success: function(){
  window.open('http://YOUR_URL','_blank' );
},

otherwise you can handle smartly to open your Excel download link in new tab with jQuery trigger function or etc.