SyntaxError:位于0的JSON中的意外标记<Angular Post Request to PHP

I am using angular 2, and I am trying to send data from angular through a post request to a php file on my server. When I try, I get this error "SyntaxError: Unexpected token < in JSON at position 0". Here is the code I have so far. Any assistance would be appreciated. Thanks!

App component button

<button class="btn btn-primary btn-lg" (click)="postData()"> Make Post Request </button>

app component code I use this function and call it on a button in the template to send the request

postData(){
this.requestService.postSomeData()
  .subscribe(
    data => this.postRequest = data,
    error => console.log('There is an error: ' + error),
    () => console.log("Completed Post Request!")
  );
}

Request Service code -- Here is the service I am calling in the app component

postSomeData(){
   let url = 'link to php file here';
   let jsonData = {
       name: 'my Name'
   };
   let headers = new Headers();
    headers.append('Content-Type', 'application/x-www-form-urlencoded');

    return this.http.post(url, jsonData, {headers: headers})
          .map(res => res.json());
 }

PHP File

<?php

 $postdata = file_get_contents("php://input");
 $request = json_decode($postdata);
 $name = $request->name;
 echo "Name: ".$name;

 ?>

The problem come from the fact that in the PHP (server-side I assume) there is no response returned.