Создал класс для обработки xml файла посредством сериализации

        public class Signals
        {
            [XmlArrayAttribute("SignalSource")]
            public SignalSource[] Items;            
        }
        
        public class SignalSource
        {
            [XmlAttribute] public string Name;
            [XmlAttribute] public string LastValue;
            [XmlAttribute] public string UpdateTime;
            [XmlArrayAttribute("SignalSource")]
            public SignalSource[] Items;
        }

в итоге получаю

<?xml version="1.0" encoding="utf-8"?>
<Signals xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" xmlns:xsd="http://www.w3.org/2001/XMLSchema">
  <SignalSource>
    <SignalSource Name="name1" LastValue="lastvalue1" UpdateTime="updatetime1">
      <SignalSource>
        <SignalSource Name="name2" LastValue="lastvalue2" UpdateTime="updatetime2" />
        <SignalSource Name="name3" LastValue="lastvalue3" UpdateTime="updatetime3" />
      </SignalSource>
    </SignalSource>
  </SignalSource>
</Signals>

интересует как можно получить такой xml-файл

<?xml version="1.0" encoding="utf-8"?>
<Signals xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" xmlns:xsd="http://www.w3.org/2001/XMLSchema">
    <SignalSource Name="name1" LastValue="lastvalue1" UpdateTime="updatetime1">
        <SignalSource Name="name2" LastValue="lastvalue2" UpdateTime="updatetime2" />
        <SignalSource Name="name3" LastValue="lastvalue3" UpdateTime="updatetime3" />
    </SignalSource>
</Signals>